Search

This study analyzed, and optimized to address energy, cost, and environmental concerns across the globe of low-grade heat source driven combined organic Rankine cycle and vapor compression refrigeration (ORC-VCR) for multifunctional utility. The exergetic efficiency, total cost, and environmental cost of the system are taken as the indicators of the thermodynamic, economic, and environmental performance of the system, respectively. The results obtained by employing the technique for order of preference by similarity to ideal solution (TOPSIS) indicate the optimal exergetic efficiency, total cost and environmental cost be 28.4%, $69949 and, $3491 respectively. The optimal combination of the operating parameters is R602 as working fluid, 75%, and 85% isentropic efficiencies of the compressor and expander, the outlet temperature of chilled fluid at 276 K, and inlet temperatures of the ORC evaporator and the cooling water at 393 K and 313 K. Moreover, the proposed system is compared with a commercially available 66.67 kW vapor compression chiller and this comparison led to the conclusion that the higher cost ($69949) of the ORC-VCR system is a major drawback in the commercial competitiveness of these systems. However, the reduction in emission of CO2 can lead the annual saving of environmental costs up to $3491.

In this paper, the organic Rankine cycle integrated vapor compression refrigeration system has been evaluated thermodynamically and optimized using Taguchi-integrated gray relation analysis. Exerge...

Objective: To compare the operative time and post-operative pain with PEEK cage method versus autologous iliac crest bone graft in anterior cervical discectomy and fusion in the cervical spine. Material & Methods: This randomized control trial study (RCT). 90 patients with cervical disc disease, cervical stenosis with or without myelopathy and cervical trauma (fractures or facet jumps with disrupted disc) were included in the study from the Department of Neurosurgery, LGH, PINS, Lahore. Patients were evaluated with plain X-rays and MRI scans of the cervical spine. All patients underwent anterior cervical decompression and fusion. In 45 patients (group A), cervical fusion was achieved with PEEK cage method and in other 45 patients (group B), autologous Iliac Crest Bone graft was used. Results: Mean age in group A was 57.1 years and in group B, it was 54.7 years. In group A, 31.1% patients were of cervical disc disease, 28.8% of cervical degenerative stenosis and 40% were of cervical trauma. In group B, 15 patients 33.3% were of cervical disc disease, 24.4% of cervical degenerative stenosis and 42.2% were of cervical trauma. The mean Postoperative Visual Analogue Scale (VAS) score for pain was 2.8 in group A and 5.4 in group B patients. Conclusion: The patients of group A (PEEK cage method) could be easily mobilized within bed and out of bed depending upon their neurological status. Decreased operative time and less post-operative pain makes PEEK cage method superior to autologous iliac crest bone graft in anterior cervical decompression and fusion.

SAR-CoV-2 originated from China with first case reporting from Wuhan, has been declared as pandemic by WHO on March 11 2020, which has affected millions of people around the globe with 213 countries and territories infected worldwide. It has caused the death of around 0.6 million individuals with no specific or promising vaccines or treatment available until now to prevent COVID 19, which has been approved; this has led the world to a global crisis not only on the health front but also affected the economic sectors. Researchers across the globe are working around the clock with their level best to discover promising therapeutic approaches for COVID 19, but till now for the treatment, only 3 therapeutics have been approved, including dexamethasone in U.K. and Japan, Avigan in Russia, Italy, and China and remdesivir in Japan and Australia; also convalescent plasma therapy is seen to be effective in critical cases of COVID-19, however, there are limitations with the use of this plasma therapy like the time point of treatment, optimal dose as the dose may vary with number of patients the particular therapeutic effects of convalescent plasma therapy will be further explored in randomized clinical trials. Several complete multinational studies are investigating alternative therapies. More than 100 countries entered a cooperation to evaluate applicants for high-profile COVID-19 diagnosis with this most massive WHO's cooperation. According to WHO's information, there are 28 vaccine candidates under clinical evaluation, with 6 of them entering phase 3. This review emphasizes the allopathic approaches along with the Chinese herbal medicine for the prevention of COVID-19. This paper also includes a brief discussion on the vaccine and nutritional supplements. Keywords: SAR-CoV-2, COVID-19, therapeutics, drugs, vaccines

Place: United States; BACKGROUND: The knowledge of proximal femur geometry is essential in the understanding and treatment of hip pathologies. Our aim is to evaluate the range of "normal anatomical values of the proximal femur" and their relationship to age, gender, and ethnicity in a cohort of healthy population, using a 3-dimensional computed tomography automated software.METHODS: The pelvis and bilateral femora of 628 healthy individuals (394 males/234 females, mean age 61.5 ± 16.5 years, mean body mass index [BMI] 26.9 ± 5.2 kg/m(2)) including 2 ethnicities (226 Asians and 406 Caucasians) were assessed with a 3-dimensional computed tomography scan-based system using algorithm-calculated landmarks. The demographic parameters recorded were age, gender, BMI, and ethnicity. The femoral neck-shaft angle (NSA), femoral neck version, femoral offset (FO), and femoral canal flare index (fCFI) were calculated for each individual. Analyses were performed using SPSS version 22. P-values \textless.05 were considered to indicate statistical significance.RESULTS: Overall, the mean NSA was 124.7° (standard deviation [SD] 6.2), mean femoral neck version was 14.5° (SD 8.1), mean FO was 42.9 mm (SD 6.8), and mean fCFI was 3.4 (SD 0.5). Gender was associated with all parameters, with the females presenting more valgus and anteverted hips. Multivariate analysis revealed a lower NSA and fCFI and a higher FO for older individuals. Ethnicity and BMI were not associated with any parameters.CONCLUSION: Our results showed that there is a direct relationship of age and gender to the variations in the investigated proximal femur anatomical parameters in a large cohort of healthy individuals. Those important gender-based and age-based differences might advocate for more varus and lateralized component to reproduce preoperative anatomy of male and patients older than 50 years.

Partial knee arthroplasty (PKA) is performed to treat end-stage osteoarthritis in a single compartment. There are minimal data characterizing soft-tissue injuries for PKA with robotic and manual techniques. This cadaver study compared the extent of soft-tissue trauma sustained through robotic-arm assisted PKA (RPKA) and manual PKA (MPKA). Five surgeons prepared 24 cadaveric knees for medial PKA, including six MPKA controls and 18 RPKA assigned into three different workflows: RPKA-LB (six knees) – RPKA with legacy burr; RPKA-NB (six knees) – RPKA with new burr design; and RPKA-NBS (six knees) – RPKA with new burr design and oscillating saw. Two surgeons estimated trauma to the patellar tendon, quadriceps tendon, anterior cruciate ligament (ACL), medial collateral ligament (MCL), medial capsule, posterior capsule, and posterior cruciate ligament (PCLs) using a five-grade system: Grade 1 – complete soft tissue preservation; Grade 2 – ≤25%; Grade 3 – 26 to 50%; Grade 4 – 51 to 75%; and Grade 5 – ≥76% trauma. A total trauma grade was assigned by summing the grades. Kruskal-Wallis statistical tests were used to assess outcomes. When compared to the MPKA group, all RPKA subgroups had lower total trauma grading (p

The performance deciders (response variables) were considered in this study, namely, thermal efficiency, exergetic efficiency, exergy destructions, and expander outlet to inlet specific volume flow...

The development of tourist attractions is now highly influenced by social media. The speed at which information can be disseminated via the Internet has become an essential factor in enabling distinct tourist attractions to potentially gain high popularity in a relatively short time. This condition was not as prevalent several years ago when tourism promotion remained limited to a certain kind of media. As a consequence, rapid change in the relative popularity of tourist attractions is inevitable. Against this, knowledge of tourist attraction hotspots is essential in tourism management. This means there is a need to study how to both quickly determine the popularity level of tourist attractions and encompass a relatively large area. This article utilised tweet data from microblogging website Twitter as the basis from which to determine the popularity level of a tourist attraction. Data mining was conducted using Python and the Tweepy module. The tweet data were collected at the end of April and early May 2017, at times when there are several long holiday weekends. A Tweet Proximity Index (TPI) was used to calculate both the density and frequency of tweets based on a defined search radius. A Density Index (DI) was also used as a technique for determining the popularity. The results from both approaches were then compared to a random survey about people’s perceptions of tourist attractions in the study area. The result shows that geotagged tweet data can be used to determine the popularity of a tourist attraction, although it still only achieved a medium level of accuracy. The TPI approach used in this study produced an accuracy of 76.47%, while the DI achieved only 58.82%. This medium accuracy does indicate that the two approaches are not yet strong enough to be used for decision-making but should be more than adequate as an initial description. Further, it is necessary to improve the method of indexing and the exploration of other aspects of Twitter data.

The present work focuses on response surface methodology-backed thermodynamic analysis of organic Rankine cycle (ORC) driven by low-temperature heat sources (temperatures less than 150°C). The zeot...

Purpose: Taper corrosion related revisions have recently been reported in the orthopaedic literature. Cleaning procedure of the trunnions during hip revision is not standardised. The purpose of this bench top investigation was to understand the alterations in the trunnion dimensions and surface roughness characteristics as a result of corrosion product build-up. Methods: 8 titanium alloy trunnions and CoCr femoral heads assemblies were cyclically tested in a mechanical simulator. Following disassembly of the tested constructs, the trunnions were cleaned using 2 methods. The trunnion dimensions were measured using coordinate measuring machine, and surface roughness was measured using white light interferometry. The trunnions were reassembled with ceramic femoral heads and titanium sleeves following cleaning. Head/sleeve pull-off testing was conducted to understand the effects of cleaning methods on the pull-off strength. Results: Grade 4 corrosion was observed on all trunnions after mechanical testing. The aggressive cleaning methods had a larger impact on the surface roughness when compared to the light cleaning method. The aggressive cleaning method also decreased the taper cone angle. The pull-off strength was not affected by the cleaning method and the pull-off values were approximately 50% of the assembly loads. Conclusions: The study suggests that trunnion cleaning method may alter the surface roughness and taper cone angle of the existing trunnion. However, the effects of these changes on the pull-off strength did not reach statistical significance. Complex corrosion testing under cyclic loading conditions are warranted to understand the long-term effects of these changes.

The current paper communicates the thermodynamic investigation on non-recuperated organic Rankine cycle system employing environmentally friendly mixtures of hexane/pentane, isohexane/penta...

In the current work, analytical expressions have been coded in MATLAB 9.0 linked with REFPROP 9.0, for solar-powered ORC system integrated with conventional compound parabolic concentrator using en...

Given the goal of achieving optimal correction and alignment after knee arthroplasty or high tibial osteotomy, literature focusing on the inter-individual variability of the native knee, tibia and femur with regards to the coronal or sagittal alignment is lacking. The aim of this study was to analyse normal angular values in the healthy middle-aged population and determine differences of angular values according to inter-individual features. The first hypothesis was that common morphological patterns may be identified in the healthy middle-aged non-osteoarthritic population. The second hypothesis was that high inter-individual variability exists with regards to gender, ethnicity and alignment phenotype. A CT scan-based modelling and analysis system was used to examine the lower limb of 758 normal healthy patients (390 men, 368 women; mean age 58.5 ± 16.4 years) with available data concerning angular values and retrieved from the SOMA database. The hip–knee–ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior distal femoral angle (PDFA), posterior proximal tibial angle (PPTA) and non weight-bearing joint line convergence angle (nwJLCA) were then measured for each patient. Results were analysed for the entire cohort and based on gender, ethnicity and phenotype. The mean HKA was 179.4° ± 2.6°, LDFA: 85.8° ± 2.0°, MPTA: 85.6° ± 2.4°, PDFA: 85.2° ± 1.5°, PPTA: 83.8° ± 2.9° and nwJLCA: 1.09° ± 0.9°. Gender was associated with higher LDFA and lower HKA for men. Ethnicity was associated with greater proximal tibial vara and distal femoral valgus for Asian patients. Patients with an overall global varus alignment had more tibia vara and less femoral valgus than patients with an overall valgus alignment. Even if significant differences were found based on subgroup analysis (gender, ethnicity or phenotype), this study demonstrated that neutral alignment is the main morphological pattern in the healthy middle-aged population. This neutrality is the result from tibia vara compensated by an ipsilateral femoral valgus. III, retrospective cohort study.

Place: Germany; International audience; PURPOSE: The aim of this study was to compare alignment parameters between patients undergoing high tibial osteotomy (HTO) for knee osteoarthritis (OA) and non-arthritic controls. METHODS: Pre-operative computed tomography images from 194 patients undergoing HTO for medial knee OA and 118 non-arthritic controls were utilized. All patients had varus knee alignment (mean age: 57 ± 11 years; 45% female). The hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA) and non-weight-bearing joint line convergence angle (nwJLCA) were compared between "control group" and "HTO group". Femoral and tibial phenotypes were also assessed and compared between groups. Variables found on univariate analysis to be different between the groups were entered into a binary logistic regression model. RESULTS: The mean age was lower (Δ = 4 ± 6 years, p = 0.024), body mass index (BMI) was higher (Δ = 1.1 ± 2.8 kg/m(2), p = 0.032) and there were more females (Δ = 14%, p = 0.020) in the HTO group. The HTO group had more overall varus (7° ± 4.7° vs 4.8° ± 1.3°, p \textless 0.001). There was a significant difference in the mean mLDFA between the two groups with the HTO group having more femoral varus (88.7 ± 3.2° vs 87.3 ± 1.8°, p \textless 0.001). MPTA was similar between the groups (p = 0.881). Age was found to be a strong determinant for femoral varus (p = 0.03). CONCLUSION: Patients undergoing HTO for medial knee OA have more femoral varus compared to non-arthritic controls while tibial morphology was similar. This will be an important consideration in pre-operating planning for realignment osteotomy in patients presenting with medial knee OA and warrants further investigation. LEVEL OF EVIDENCE: III, retrospective comparative study.

Background: Anterior cruciate ligament (ACL) injuries are multifactorial events that may be influenced by morphometric parameters. Associations between primary ACL injuries or graft ruptures and both femoral and tibial bony risk factors have been well described in the literature. Purpose: To determine values of femoral and tibial bony morphology that have been associated with ACL injuries in a reference population. Further, to define interindividual variations according to participant demographics and to identify the proportion of participants presenting at least 1 morphological ACL injury risk factor. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Computed tomography scans of 382 healthy participants were examined. The following bony ACL risk factors were analyzed: notch width index (NWI), lateral femoral condylar index (LFCI), medial posterior plateau tibial angle (MPPTA), and lateral posterior plateau tibial angle (LPPTA). The proportion of this healthy population presenting with at least 1 pathological ACL injury risk factor was determined. A multivariable logistic regression model was constructed to determine the influence of demographic characteristics. Results: According to published thresholds for ACL bony risk factors, 12% of the examined knees exhibited an intercondylar notch width Conclusion: The precise definition of bony anatomic risk factors for ACL injury remains unclear. Based on published thresholds, 15% to 62% of this reference population would have been considered as being at risk. Large cohort analyses are required to confirm the validity of previously described morphological risk factors and to define which participants may be at risk of primary ACL injury and reinjury after surgical reconstruction.

In the last two decades, automation and artificial intelligence improve accuracy as well as the quality of product and reduced processing time due to enormous advancement in the technology of robotics. At the present time, the most crucial factors in the modern world are scarcity of energy resources for global demand. Due to environmental issues and legislative straining, electrification is a glaring inclination to renovate performance and sustainability of the transportation system. Solar photovoltaic technology is an important research area to convert solar energy into useful electrical power. So far, robot extracts electrical energy stored in the batteries to run its mechanical, electrical and electronic devices to perform several tasks for industrial as well as commercial work. The robot can operate in a hazardous environment for a long duration of time without human assistant with high accuracy.

Fast exhausting fossil fuel reserves and high rise in the air pollution levels due to combustion of these fuels bound us to discover some cleaner and environment-friendly fuels for the engines. Bio...

In India, the scope of renewable solar energy is admirable due to geographical nature as most of the parts received an average of 4-7 kWh solar energy per square meter. Due to the continuous rotational motion of the earth, the intensity of solar Irradiation is irregular and varies from time to time. Controlling the output voltage of Photovoltaic modules is the key task to increase the efficiency and maximise output electrical energy. In the present work, modelling of Photovoltaic module and power obtained from the module is discussed. Next, designing of DC-boost converter using pulse width modulation control technic for the solar electric vehicle is presented. After that, modelling of DC-DC power/boost converter for a hybrid electric vehicle using MATLAB® Simscape library tool is presented. Thereafter, simulations to boost up or enhance the photovoltaic output voltage have been carried out in MATLAB Simscape library tool.

The present work seeks to assess the sustainability of different solar photovoltaic (SPV) electricity-generating systems based upon energy, environment and economics. The sustainability indicators ...

Conventional energy resources are depleting very fast and to meet the global energy demand, the scarcity of these resources is the most crucial factor in the present era. One of the major contributors to carbon emissions is transportation sector which survives mostly on conventional energy resources. In the Indian context, the transportation sector contributes about 18% of CO2 emissions of total emissions. To decarbonize this sector, the vehicles utilizing renewable resources such as solar PV technology would be a sustainable step. Solar energy which is abundant in nature and present everywhere can prove to be a great alternative to conventional resources. In the present study, solar PV technology is integrated with electric and hybrid vehicles. Additional literature review of solar electric vehicles including three-wheeled as well as four-wheeled is carried out. Autonomous vehicles and robots utilizing PV technology are also studied and presented. Finally, the foremost barriers and challenges to adopting PV technology in electric and autonomous vehicles are identified and presented.

Purpose Diesel engine can produce power more efficiently with lower exhaust emissions when operated at optimum input parameter settings. To achieve this goal, the purpose of this paper is to optimize the input parameters of diesel engine which will lead to optimum performance and exhaust emissions. Design/methodology/approach To achieve the goal of improving diesel engine performance and exhaust emissions, four input parameters were considered in the study. Five different levels of each input parameter were taken. Four response variables under no load, half load and full load conditions were recorded. Experiments were performed in random manner according to selected Taguchi L25 orthogonal array. The data were analyzed using grey relational analysis coupled with principal component analysis. Analysis of S/N ratio was performed to obtain the optimum combination of input parameters. The grey relational grade at optimum setting of the input parameters was obtained by regression analysis. Findings Results of the current research work give the optimum input parameter settings for no load, half load and full load conditions of diesel engine. Engine produces power more efficiently with low exhaust emissions when operated at these optimum settings. Practical implications In view of the compliance to the stringent air pollution norms of the nations and fast depleting fossil fuels, it is of the utmost importance to design and operate the engine in the optimum range of its input parameters so that it produces more power with low exhaust emissions. This paper aims at optimizing input parameters of diesel engine to improve performance and exhaust emissions. Results of the study presented in this paper are significantly useful for diesel engine-related researchers and professionals. Originality/value From the literature review, it appears that only few researchers have conducted studies pertaining to the optimization of the input parameters of diesel engine to improve performance or exhaust emissions. Although few studies related to the optimization of compression ratio, fuel injection timing, fuel injection pressure and air pressure have been reported, no work related to optimization of temperature and pressure of turbocharged air has been reported. Therefore, the main focus of the current research work is on optimizing the charge air temperature and pressure with respect to performance and exhaust emissions.

This paper communicates the performance of low-grade solar heat source powered Organic Rankine Cycle (ORC).To investigate the system performance, first law and exergetic efficiencies, power output are evaluated and compared for zeotropic mixtures of (iso)butane / (iso)pentane and cyclohexane/R123.The results indicate that there exists an optimal mass fraction for which energy and exergetic efficiencies, and power output are maximum correspondings to a given value of expander inlet temperature compared to pure fluids. However, the specific volume flow ratio of the expander is higher for zeotropic mixtures; which results in lower economy of mixtures than pure fluids. The use of internal heat exchanger in the system improves cycle performance. Moreover, multi-objective genetic algorithm further improves the performance of ORC and exhibits better exergetic efficiency 51-57% and 0-14.09% reduction in lower expander specific volume flow ratio (v6/v5), than thermodynamically optimized organic Rankine cycle.

The orientation and distance from the shaft of the femur and tibia to the articular surface centre is important for performing total knee arthroplasty (TKA) with cementless stems. It is important to understand anatomic differences between races to match the tibial and femoral shaft axis to the knee articular surface. Thus, the purpose of this study was to compare knee morphology between Caucasian and East Asian individuals to determine the optimal placement of tibial and femoral stems. A retrospective study was conducted on a matched cohort of 50 East Asians (21F, 29M) and 50 Caucasians (21F, 29M) by age and gender. CT scans were obtained in healthy volunteers using

Purpose The purpose of this paper is to investigate the effect of four controllable parameters (fuel mixture, evaporation bubble point temperature, expander inlet temperature and condensation dew point temperature) of a solar-driven organic Rankine cycle (ORC) on the first-law efficiency, the exergetic efficiency, the exergy destruction and the volume flow ratio (expander outlet/expander inlet). Design/methodology/approach Nine experiments as per Taguchi’s standard L9 orthogonal array were performed on the solar-driven ORC. Subsequently, multi-response optimization was performed using grey relational and principal component analyses. Findings The results revealed that the grey relational analysis along with the principal component analysis is a simple as well as effective method for solving the multi-response optimization problem and it provides the optimal combination of the solar-driven ORC parameters. Further, the analysis of variance was also employed to identify the most significant parameter based on the percentage of contribution of each cyclic parameter. Confirmation tests were performed to check the validity of the results which revealed good agreement between predicted and experimental values of the response variables at optimum combination of the input parameters. The optimal combination of process parameters is the set with A3 (the best fuel mixture in the context of optimal performance is 0.9 percent butane and 0.1 percent pentane by weight), B2 (evaporation bubble point temperature=358 K), C1 (condensation dew point temperature=300 K) and D3 (expander inlet temperature=370 K). Research limitations/implications In this research, the Taguchi-based grey relational analysis coupled with the principal components analysis has been successfully carried out, whereas for any optimized solution, it is required to have a real-time scenario that may be taken into consideration by the application of different soft computing techniques like genetic algorithm, simulated annealing, etc. The results generated are purely based on theoretical modeling, and, for further research, experimental analyses are required to consolidate the generated results. Originality/value This piece of research work will be helpful to users of solar energy, academicians, researchers and other concerned persons, in understanding the importance, severity and benefits obtained by the application, implementation and optimization of the cyclic parameters of the solar-driven ORC.

Background: Several 2-dimensional and 3-dimensional surfaces are available for cementless acetabular fixation. Plain radiographs are used to assess osseointegration; however, the radiographs are limited by their inability to capture the bone fixation process occurring over the 3-dimensional cup surface. In this cadaveric study, we compared the bone apposition between 2-dimensional and 3-dimensional cups. Methods: Both types of cups were implanted in 6 cadavers and pelvic radiographs obtained. Each cup was resected from the pelvis with adequate bone around it, and subsequently embedded in a polymer. Six sections of each cup were obtained to examine the metal and bone interface. Photographs and contact radiograph images were obtained for each section, and these were graded to arrive at percent metal-bone contact values for the cups. Results: On average

This paper communicates detailed energy and exergy analysis of low-grade energy resource of solar-powered organic Rankine cycle (ORC) integrated with both the internal heat exchanger and open feed water heater, ORC incorporated with the internal heat exchanger, with open feed water heater and basic ORC, respectively. Results indicate that highest first law efficiency (11.9%), exergetic efficiency (51.88%) and lowest exergy destruction (1749 kW) are obtained for ORC integrated with both internal heat exchanger and open feed water heater among other considered ORCs. Moreover, zeotropic mixture (butane/R1234yf) shows better first law and exergetic efficiency and lower exergy destruction than pure fluid.

International audience; Purpose In cases where the femur or tibia exhibits abnormal mechanical angulation due to degenerative changes or fracture, the contralateral leg is often used to complete preoperative templating. The aim of this study was to determine the degree of asymmetry between knee joints in healthy individuals and to determine whether it is affected by differing demographic parameters. Methods A CT scan-based modelling and analysis system was used to examine the lower limb of 233 patients (102 males, 131 women; mean age 61.2 ± 15.2 years, mean body mass index 24.9 ± 4.4 kg/m 2) The hip-knee angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior proximal tibial angle (ppta) and posterior distal femoral angle (PDFA) were then calculated for each patient. Results were then analysed to calculate femoral symmetry based on absolute differences (AD) and percentage asymmetry (%AS) using a previously validated method. Results Our results do not demonstrate any considerable asymmetry (percentage of asymmetry > 2%) for all the anatomical parameters analysed: HKA (mean AD = 1.5°; mean AS % = 0.8, n.s), MPTA (AD = 1.1°; AS % = 1.3, n.s), PPTA (AD = 1.4°; AS % = 1.0, n.s), LDFA (AD = 1.2 mm; AS % = 1.4, n.s) and PDFA (AD = 0.9°; AS % = 1.0, n.s). Gender and ethnicity were not associated with significantly higher AD asymmetry. A significant correlation of AD asymmetry was observed between BMI and HKA, BMI and MPTA, and between patients' age and the MPTA.Conclusion: This data demonstrate that there is a non-statistically significant mechanical angle asymmetry between the two lower limbs. In cases where contralateral templating is used, such asymmetry will induce minimal (if any) clinical differences.

Growing demand of electricity is a challenge which affects the fate of our economy. Punjab is the major consumer of electricity which consumes more than 60 % of electricity produced. Energy conservation is one of the step towards decreasing the demand supply gap. Punjab Energy Efficiency and Conservation Agency (PEECA) conducted energy audits of public sector institutes in order to find the conservation potential which leads towards the retrofitting of conventional electrical appliances with efficient ones for relieving the burden on national grid. PEECA had chosen Government College University Lahore as a pilot project and retrofitted efficient electrical appliances by finding energy conservation potential. In this paper, energy conservation targets are highlighted which were achieved after the retrofitting of efficient electrical appliances in GCU Lahore. Moreover, it has also been demonstrated that if efficient electrical appliances would be retrofitted in other public institutes of Punjab, then huge amount of energy can be saved.

Background Component positioning in total hip arthroplasty (THA) is among the primary indicators for longevity and success. Acetabular component positioning has been discussed in literature at length; however, femoral component positioning is also important as it contributes to combined anteversion. Methods In this study, we examined the changes in femoral anteversion after the implantation of anatomic stem ABG II. A cadaveric study, a computed tomography–based computer modeling study, and a clinical study using a navigation system were conducted to document these changes. Results These studies demonstrated that the anatomic stem ABG II increased the postimplantation femoral version by approximately 7°. The postimplantation versions followed a bimodal distribution. The computed tomography and navigation data also highlighted that the patient population may roughly be divided into 2 groups: the first group that needs anteverted stem and the second group that needs little or no anteversion in the stem to recreate the desired version and offset. Conclusion Based upon our data, we propose a new anatomic stem design that is offered in 2 version angles of 0° and 7° to help create the desired version and offset.

Background:There is no general consensus on the normal and pathological values for the posterior tibial slope (PTS).Purpose/Hypothesis:The primary aim of this study was to determine standard values for the PTS in healthy participants using 3-dimensional (3D) computed tomography (CT). A secondary aim was to determine the effect of demographic factors and coronal-plane lower limb alignment on the PTS measurement. The hypothesis was that the PTS would be significantly influenced by demographic factors and coronal-plane lower limb alignment.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A CT-based modeling and analytics system was used to examine and measure lower limb alignment and the PTS in 378 patients (193 male and 185 female; mean age, 58.3 ± 16.4 years [range, 18-92 years]; mean body mass index, 25.0 ± 4.4 kg/m2). The lateral, medial, and global PTS were measured for each patient. All measurements were constructed using algorithm-calculated landmarks, resulting in reproducible and consistent constructs for each specimen. The results were then evaluated based on ethnicity, sex, and hip-knee-ankle (HKA) angle.Results:The study population comprised 219 white and 159 Asian participants. The mean global, medial, and lateral PTS were 6.3° (range, –5.5° to 14.7°; 1% with ≥12°), 6.2° (range, –4.1° to 17.2°; 3% with ≥12°), and 5.3° (range, –4.7° to 16.2°; 2% with ≥12°), respectively. The lateral (Δ = –1.0° [95% CI, 0.6°-1.6°]; P < .0001) and global (Δ = –0.5° [95% CI, 0.0°-0.8°]; P = .0332) PTS were smaller in the female subpopulation. The global PTS was greater (Δ = 1.9° [95% CI, 1.5°-2.3°]; P < .0001) in the Asian subpopulation. The mean HKA angle was 179.6° (range, 170°-190°). The HKA angle was significantly correlated with the medial and global PTS. Specimens with a genu varum knee exhibited a significantly greater global (Δ = 1.2° [95% CI, 0.8°-1.7°]; P < .0001) and medial (Δ = 1.9° [95% CI, 1.3°-2.5°]; P < .0001) PTS.Conclusion:The present study gives a benchmark for the physiological values of the PTS in a healthy population and highlights several factors influencing the PTS, such as ethnicity, sex, and alignment. Anatomic variants with a PTS ≥12° were very uncommon (≤3%) in our Asian and white groups and thus could be considered as pathological. The PTS is a crucial anatomic factor for anterior cruciate ligament injuries and reconstruction. A general consensus is lacking regarding the cutoff for abnormal values, thus guiding standard of care. This study investigated the dispersion of global, medial, and lateral posterior plateau tibial angles in a large population representing a range of demographic diversity.

Assembly of a femoral head onto the stem remains non-standardized. The literature shows altering mechanical conditions during seating affects taper strength and lower assembly load may increase fretting corrosion during cyclic tests. This suggests overall performance may be affected by head assembly method. The purpose of this test was to perform bench-top studies to determine influence of peak force magnitude, load rate, and compliance of the system's support structure on initial stability of the taper. Custom manufactured CoCrMo femoral heads and Ti-6Al-4V taper analog samples were assembled with varying peak force magnitudes (2–10.1 kN), load rates (quasi-static vs impaction), and system compliance (rigid vs compliant). A clinically-relevant system compliance design was based off of force data collected during a cadaver impaction study. Tensile loads were then applied to disassemble the taper and quantify initial taper stability. Results indicated that taper stability (assessed by disassembly forces) increased linearly with assembly force and load rate did not have a significant effect on taper stability. When considering system compliance, a 42%–50% larger input energy, dependent on assembly force, was required in the compliant group to achieve a comparable impaction force to the rigid group. Even when this impaction force was achieved, the correlation between the coefficient, defined as distraction force divided by assembly load, was significantly reduced for the compliant test group. The compliant setup was intended to simulate a surgical scenario where patient and surgical factors may influence the resulting compliance. Based on results, surgical procedure and patient variables may have a significant effect on initial taper stability.

Aims In patients where the proximal femur shows gross deformity due to degenerative changes or fracture, the contralateral femur is often used to perform preoperative templating for hip arthroplasty. However, femurs may not be symmetrical: the aim of this study was to determine the degree of variation between hips in healthy individuals and to determine whether it is affected by demographic parameters. Materials and Methods CT-scan based modelling was used to examine the pelvis and bilateral femurs of 345 patients (211 males, 134 women; mean age 62 years (standard deviation (sd) 17), mean body mass index 27 kg/m2 (sd 5)) representing a range of ethnicities. The femoral neck-shaft angle (NSA), femoral offset (FO), femoral neck version (FNV), femoral length (FL), femoral canal flare index (fCFI), and femoral head radius (FHr) were then determined for each patient. All measurements were constructed using algorithm-calculated landmarks, resulting in reproducible and consistent constructs for each specimen. We then analyzed femoral symmetry based on absolute differences (AD) and percentage asymmetry (%AS) following a previously validated method. Results We found an asymmetry > 2% for NSA (mean AD 2.9°, mean %AS 2.3; p = 0.03), FO (AD 3.8 mm, %AS 9.1 ; p = 0.01), FNV (AD 5.1°, %AS 46.7 ; p = 0.001) and fCFI (AD 0.2 mm, %AS 5.4 ; p = 0.7). Significant relationships were found for AD regarding NSA and ethnicity (p = 0.037), FL and height (R2 = 0.22), and fCFI and gender (R2 = 0.34). Conclusion Our data confirm the presence of asymmetry of proximal femurs, which is mostly independent of demographic parameters. In cases where contralateral templating is used, such asymmetry may lead to inaccurate anatomical restoration of the hip if the templated sizes are routinely implanted. However, the clinical impact cannot be determined from our investigation. Cite this article: Bone Joint J 2018;100-B:839–44.

Most current tapered wedge hip stems were designed based upon the original Mueller straight stem design introduced in 1977. These stems were designed to have a single medial curvature and grew laterally to accommodate different sizes. In this preclinical study, the design and verification of a tapered wedge stem using computed tomography scans of 556 patients are presented. The computer simulation demonstrated that the novel stem, designed for proximal engagement, allowed for reduced distal fixation, particularly in the 40-60 year male population. Moreover, the physical micromotion testing and finite element analysis demonstrated that the novel stem allowed for reduced micromotion. In summary, preclinical data suggest that the computed tomography based stem design described here may offer enhanced implant fit and reduced micromotion.

Study design A biomechanical finite element modeling study of the human lumbar spine. Objective To evaluate the effects of a transforaminal interbody device's footprint on lumbar spine biomechanics to further examine the potential subtle biomechanical differences not captured in previous studies. Summary of background data In recent years, the evolution of interbody fusion devices has provided the surgeons with a multitude of options. An articulating transforaminal lumbar interbody fusion (TLIF) device is developed to overcome the surgical challenges associated with insertion of a large footprint interbody device through a small incision. Methods A finite element model of the L3-S1 lumbar segment was modified to simulate replacement of various TLIF constructs with different cage designs including an articulating vertebral interbody (AVID) TLIF device and a generic TLIF device placed in different configurations. The instrumented models were subjected to a 400 N follower load along with a 10 N m bending moment at different physiological planes. The kinematics, loads, and stresses were compared among various models. Results Simulated cage designs provided similar kinematical stability within the treated segments. However, the articulating and double TLIF implants allowed for better load sharing through the anterior column. These implants resulted in lower endplate and pedicle screw stresses and in more homogenous stress distribution across the peripheral region of the endplate. Conclusions An articulating, large footprint, peripherally placed TLIF device affords substantial biomechanical advantages. This device may be able to reduce the incidence of subsidence because of its ability to reduce and distribute the endplate stresses in the stronger peripheral region. It may also reduce the posterior hardware failure incidence owing to its ability to reduce the screw stresses as compared with traditional TLIF. Although double TLIF has been demonstrated to have similar biomechanical advantages as the AVID, complications associated with double TLIF (ie, larger surgical incision, longer surgical procedure, placement and alignment challenges) support AVID as a better optimized alternative.

The aim of this paper is to optimise the input parameters of a diesel engine which results in optimum performance and emission. Four input parameters viz., compression ratio, fuel injection timing, air temperature and air pressure were considered in this study. Four response variables i.e., brake thermal efficiency, brake specific fuel consumption, hydrocarbon emission and smoke opacity were measured. Twenty five experiments as per Taguchi L25 orthogonal array were performed and experimental data was analysed using grey relational analysis (GRA) to accomplish multi response optimisation. Regression analysis was done to determine the experimental value of the grey relational grade (GRG) at optimum setting of the input parameters. In order to validate the experimental results, the experimental value of the GRG was compared with the predicted value and the comparison revealed good relation between the predicted and experimental values of the GRG at optimum combination of the input parameters.

Porous metaphyseal cones are widely used in revision knee arthroplasty. A new system of porous titanium metaphyseal cones has been designed based on the femoral and tibial morphology derived from a computed tomography-based anatomical database. The purpose of this study is to evaluate the initial mechanical stability of the new porous titanium revision cone system by measuring the micromotion under physiologic loading compared with a widely-used existing porous tantalum metaphyseal cone system.The new cones were designed to precisely fit the femoral and tibial anatomy, and 3D printing technology was used to manufacture these porous titanium cones. The stability of the new titanium cones and the widely-used tantalum cones were compared under physiologic loading conditions in bench top test model.The stability of the new titanium cones was either equivalent or better than the tantalum cones. The new titanium femoral cone construct had significantly less micromotion compared with the traditional femoral cone construct in 5 of the 12 directions measured (P.05), whereas no statistical difference was found in 7 directions. The new porous titanium metaphyseal tibial cones demonstrated less micromotion in medial varus/valgus (P = .004) and posterior compressive micromotion (P = .002) compared with the traditional porous tantalum system.The findings of this biomechanical study demonstrate satisfactory mechanical stability of an anatomical-based porous titanium metaphyseal cone system for femoral and tibial bone loss as measured by micromotion under physiologic loading. The new cone design, in combination with instrumentation that facilitates surgical efficiency, is encouraging. Long-term clinical follow-up is warranted.

Background The incidence of revision hip arthroplasty is increasing with nearly 100,000 annual procedures expected in the near future. Many surgeons use straight modular tapered stems in revisions; however, complications of periprosthetic fracture and cortical perforation occur, resulting in poor outcomes. Our objective was to identify patient demographics and femoral characteristics that predispose patients to cortical perforation when using the straight modular stems. Methods We used a computed tomography database and modeling software to identify patient demographics and morphologic femoral characteristics that predispose patients to cortical perforation during revision hip arthroplasty. Overall, 561 femurs from patients of various backgrounds were used, and statistical analysis was performed via the 2-sample t test. Results Decreased patient height (mean 163.0 vs 168.8 cm), radius of curvature (818 vs 939 mm), anterior–posterior (8.5 vs 13.8 mm) and medial–lateral (7.9 vs 11.3 mm) width of the isthmus, and distance of the isthmus from the greater trochanter (179 vs 186 mm) were all statistically significant risk factors for cortical perforation ( P Conclusion This study identifies several patient-specific risk factors for cortical perforation during revision hip arthroplasty using straight modular tapered stems and highlights the importance of preoperative planning especially in patients with shorter stature, proximal location of the femoral isthmus, narrow femoral canal, and smaller radius of curvature. Also, when using a mid-length modular tapered stem without an extended trochanteric osteotomy, consideration should be given to using a kinked stem to avoid anterior cortical perforation.

Background Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system. Methods In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.6 N + varying moment). Findings The bi-level fusion models are more than twice as stiff as compared to the intact model during flexion-extension, lateral bending and axial rotation. Bi-level disc replacement model required moments lower than intact model (1.5 Nm). Fusion plus disc replacement model required moment 10–25% more than intact model, except in extension. Adjacent level motions, facet loads and endplate stresses increased substantially in the bi-level fusion model. On the other hand, adjacent level motions, facet loads and endplate stresses were similar to intact for the bi-level disc replacement model. For the fusion plus disc replacement model, adjacent level motions, facet loads and endplate stresses were closer to intact model rather than the bi-level fusion model, except in extension. Interpretation Based on our finite element analysis, fusion plus disc replacement procedure has less severe biomechanical effects on adjacent levels when compared to bi-level fusion procedure. Bi-level disc replacement procedure did not have any adverse mechanical effects on adjacent levels.

Anterior cervical discectomy and fusion (ACDF) represent the standard treatment for cervical spondylolytic radiculopathy and myelopathy. To achieve solid fusion, appropriate compressive loading of the graft and stability are essential. Fusion may lead to adjacent segment degeneration. Artificial discs have been introduced as motion-preserving devices to reduce the risk of fusion-related complications.We therefore asked: (1) Does the use of a plate reduce motion at the operated level and bone graft compression compared to fusion with bone graft alone; and (2) is adjacent-segment motion higher after fusion with a plate?Motions and compressive loads in the graft were quantified for intact, C4-C5 ACDF without and with a plate, and total disc arthroplasty in human cadaver spines.At the surgery level all motions decreased for ACDF with a plate. The motions were similar to intact motions after total disc arthroplasty. The motions across the adjacent segment increased after fusion in all loading modes except lateral bending and were closer to the intact for the total disc arthroplasty case. The plate maintained a compressive load on the graft with a maximum increase in extension.Unlike fusion, the arthroplasty can restore motion to normal at the surgery and adjacent segments, compared to fusion cases. A cervical plate with a precompression of the graft provides enhanced stability and fusion due to improved compression.Our findings support the clinical observations that fusion may lead to the degeneration of the adjacent segments. Disc arthroplasty may be able to circumvent the adjacent segment degeneration.

Study Design. This is an in vitro biomechanical study. Objective. To compare the biomechanical stability of the 3 C1-C2 transarticular screw salvaging fixation techniques. Summary and Background Data. Stabilization of the atlantoaxial complex is a challenging procedure because of its complicated anatomy. Many posterior stabilization techniques of the atlantoaxial complex have been developed with C1-C2 transarticular screw fixation been the current gold standard. The drawback of using the transarticular screws is that it has a potential risk of vertebral artery injury due to a high riding transverse foramen of C2 vertebra, and screw malposition. In such cases, it is not recommended to proceed with inserting the contralateral transarticular screw and the surgeon should find an alternative to fix the contralateral side. Many studies are available comparing different atlantoaxial stabilization techniques, but none of them compared the techniques to fix the contralateral side while using the transarticular screw on one side. The current options are C1 lateral mass screw and short C2 pedicle screw or C1 lateral mass screw and C2 intralaminar screw, or C1-C2 sublaminar wire. Methods. Nine fresh human cervical spines with intact ligaments (C0-C4) were subjected to pure moments in the 6 loading directions. The resulting spatial orientations of the vertebrae were recorded using an Optotrak 3-dimensional Motion Measurement System. Measurements were made sequentially for the intact spine after creating type II odontoid fracture and after stabilization with unilateral transarticular screw placement across C1-C2 (TS) supplemented with 1 of the 3 transarticular salvaging techniques on the contralateral side; C1 lateral mass screw and C2 pedicle screw (TS+C1LMS+C2PS), C1 lateral mass and C2 intralaminar screw (TS+C1LMS+C2ILS), or sublaminar wire (TS + wire). Results. The data indicated that all the 3 stabilization techniques significantly decreased motion when compared to intact in all the loading cases (left/right lateral bending, left/right axial rotation, flexion) except extension. All the 3 instrumented specimens were equally stable in extension/flexion and lateral bending modes. TS+C1LMS+C2PS was equivalent to TS+C1LMS+C21LS (P> 0.05) and superior to TS + wire in axial rotation (P < 0.05). Also, TS+C1 LMS+C21LS was superior to TS + wire in axial rotation (P < 0.05). Conclusion. Fixation of atlantoaxial complex using unilateral transarticular screw supplemented with contralateral C1 lateral mass and C2 intralaminar screws is biomechanically equivalent to C1 lateral mass and C2 pedicle screws and both are biomechanically superior to C1-C2 sublaminar wire in axial rotation.

Sustainable development requires methods and tools to measure and compare the environmental impacts of human activities for various products viz. goods, services, etc. This paper presents a review of life cycle assessment (LCA) of solar PV based electricity generation systems. Mass and energy flow over the complete production process starting from silica extraction to the final panel assembling has been considered. Life cycle assessment of amorphous, mono-crystalline, poly-crystalline and most advanced and consolidate technologies for the solar panel production has been studied.

Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many artificial disc designs claim to restore the normal kinematics of the cervical spine. What differentiates one type of design from another design is currently not well understood. In this study, authors examined various clinically relevant parameters using a finite element model of C3–C7 cervical spine to study the effects of variations of ball and socket disc designs. Four variations of ball and socket-type artificial disc were placed at the C5–C6 level in an experimentally validated finite element model. Biomechanical effects of the shape (oval vs. spherical ball) and location (inferior vs. superior ball) were studied in detail. Range of motion, facet loading, implant stresses and capsule ligament strains were computed to investigate the influence of disc designs on resulting biomechanics. Motions at the implant level tended to increase following disc replacement. No major kinematic differences were observed among the disc designs tested. However, implant stresses were substantially higher in the spherical designs when compared to the oval designs. For both spherical and oval designs, the facet loads were lower for the designs with an inferior ball component. The capsule ligament strains were lower for the oval design with an inferior ball component. Overall, the oval design with an inferior ball component, produced motion, facet loads, implant stresses and capsule ligament strains closest to the intact spine, which may be key to long-term implant survival.

Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement. A partially truncated hemispherical shell was designed with an offset center of rotation, thick superior rim, and beveled anterior and superior rims as an alternative to a conventional jumbo cup. A three dimensional computer simulation was used to assess head center position and safe screw trajectories. Results of this in vitro study indicate that a modified hemispherical implant geometry can reduce head center elevation while permitting favorable screw fixation trajectories into the pelvis in comparison to a conventional jumbo cup.

Background context Biomechanical studies of artificial discs that quantify parameters such as load sharing and stresses have been reported in literature for single-level disc placements. However, literature on the effects of using the Charite artificial disc (ChD) at two levels (2LChD) as compared with one-level fusion (using a cage [CG] and a pedicle screw system) plus one-level artificial disc combination (CGChD) is sparse. Purpose To determine the effects of the 2LChD and CGChD across the implanted and adjacent segments. Study design A finite element model of a L3–S1 segment was used to compare the biomechanical effects of the ChD placed at two lower levels (2LChD model) with L5–S1 fusion (using a CG and a pedicle screw system) plus L4–L5 level ChD placement combination (CGChD model). Methods We used our recently published and experimentally validated L3–S1 finite element model for the present study. The intact model was subjected to 400 N axial compression and 10.6 Nm of flexion/extension moments. The experimental constructs described above were then subjected to 400 N axial compression and a moment that produced overall motion equal to the intact model predictions (hybrid testing protocol). Resultant motion, loads across facets, and other parameters were analyzed at the experimental and adjacent levels. Results In flexion, the bending moments for the CGChD and 2LChD models were 15.4 Nm (fusion effect) and 7.3 Nm (increase in flexibility effect), respectively in comparison to 10.6 Nm for the intact model. The corresponding values in the extension mode were 11.2 Nm and 7.2 Nm. The predicted flexion rotations across the L5–S1 segment for the CGChD decreased by 76% (fusion effect), and increased at the L4–L5 and the L3–L4 levels by 68.5% and 28%, respectively. In the extension mode, motion across the L5–S1 segment decreased by 96.4% whereas it increased 74.6% and 18.2% across the L4–L5 and L3–L4 levels, respectively. For the 2LChD model, the flexion rotation across the L5–S1 segment increased by 28.2%. The motions across the L4–L5 and L3–L4 segments decreased by 12% and 24%, respectively. In extension, the corresponding changes were 10% increase, 10% increase, and 21% decrease at the L5–S1, L4–L5, and L3–L4 levels, respectively. The facet loads were in line with the changes in motion, except for the 2LChD case. Conclusions The changes at L3–L4 level for both of the cases were of similar magnitude (approximately 25%), although in the CGChD model it increased and in the 2LChD model it decreased. The changes in motion at the L4–L5 level were large for the CGChD model as compared with the 2LChD model predictions (approximately 70% increase vs. 10% increase). It is difficult to speculate if an increase in motion across a segment, as compared with the intact case, is more harmful than a decrease in motion.

The purpose of this study was to (1) develop a three-dimensional, nonlinear pediatric lumbar spine finite element model (FEM), and (2) identify the mechanical reasons for the posterior apophyseal bony ring fracture in the pediatric patients. The pediatric spine FE model was created from an experimentally validated three-dimensional adult lumbar spine FEM. The size of the FEM was reduced to 96% taking into account of the ratio of the sitting height of an average 14-years-old children to that of an adult. The pediatric spine was created with anatomically specific features like the growth plate and the apophyseal bony ring. For the stress analyses, a 10-N m moment was applied in all the six directions of motion for the lumbar spine. A preload of 351 N was applied which corresponds to the mean body weight of the 14-years-old group. The stresses at the apophyseal bony ring, growth plate and endplate were calculated. The results indicate that the structures surrounding the growth plate including apophyseal bony ring and osseous endplate were highly stressed, as compared to other structures. Furthermore, posterior structures in extension were in compression whereas in flexion they were in tension, with magnitude of stresses higher in extension than in flexion. Over time, the higher compression stresses along with tension stresses in flexion may contribute to the apophyseal ring fracture (fatigue phenomena).

This paper presents detailed energy and exergy analysis and comparison of low-grade solar heat source powered superheated and saturated organic Rankine cycle (ORC) using zeotropic mixture butane/R1234ze. The required expression to evaluate the power output, first law efficiency exergetic efficiency, exergy destruction, and required heat exchangers area are coded in Matlab 2015a interfaced with REFPROP 9.0. Moreover, saturated and superheated ORCs are further optimized by genetic algorithm by selecting exergetic efficiency and product of overall heat transfer coefficient and heat exchanger area. It is observed that superheated ORC exhibits better net power output, first law, and exergetic efficiency, lower exergy destruction, and poorer economy than saturated ORC. Further, the performance of saturated ORC is increased by 34.02% and that of superheated ORC by 17.06% by the multiobjective genetic algorithm.

Diesel engines convert chemical energy into mechanical energy generally with low efficiency. However, if these engines are operated at optimum levels of input parameters, they can produce power more efficiently with minimum harmful exhaust emissions. The current research work is carried out with an aim to determine these optimum levels of the input parameters. Four input parameters were selected and their optimum combinations were determined using Taguchi based technique for order of preference by similarity to ideal solution (TOPSIS) coupled with Entropy Weight method. Taguchi's L25 orthogonal array was adopted to perform the experiments. All the test runs were carried out in random manner with three replicates of each to improve the accuracy of the experiments. The preference values (relative closeness of the distinct alternative to the positive ideal solution) predicted by Taguchi method and the values obtained by regression analysis, at optimum input parameter settings were compared and a good relationship was found between them.

Lumbar spondylolysis is a stress fracture of the pars interarticularis. We have evaluated the site of origin of the fracture clinically and biomechanically. Ten adolescents with incomplete stress fractures of the pars (four bilateral) were included in our study. There were seven boys and three girls aged between 11 and 17 years. The site of the fracture was confirmed by axial and sagittal reconstructed CT. The maximum principal tensile stresses and their locations in the L5 pars during lumbar movement were calculated using a three-dimensional finite-element model of the L3-S1 segment. In all ten patients the fracture line was seen only at the caudal-ventral aspect of the pars and did not spread completely to the craniodorsal aspect. According to the finite-element analysis, the higher stresses were found at the caudal-ventral aspect in all loading modes. In extension, the stress was twofold higher in the ventral than in the dorsal aspect. Our radiological and biomechanical results were in agreement with our clinical observations.

Mycobacterium tuberculosis is the causative agent of the disease, tuberculosis and H37Rv is the most studied clinical strain. We use comparative genome analysis of Mycobacterium tuberculosis H37Rv and human for the identification of potential targets dataset. We used DEG (Database of Essential Genes) to identify essential genes in the H37Rv strain. The analysis shows that 628 of the 3989 genes in Mycobacterium tuberculosis H37Rv were found to be essential of which 324 genes lack similarity to the human genome. Subsequently hypothetical proteins were removed through manual curation. This further resulted in a dataset of 135 proteins with essential function and no homology to human.

Study design The assessment of L3 and L4 pars interarticularis thickness and finite element analysis of stress distribution across L3 and L4 pars interarticularis. Objective To quantify the morphology of the region of the L3 and L4 pars interarticularis and to assess the stress increase as a function of access size using the finite element lumbar spine model. Summary of background data Inadequate decompression and traction of the nerve structures are several causes of the unsatisfactory outcomes in patients after foraminal stenosis decompression and far lateral disc herniation removal by extraforaminal exposure. Enlarging the access of the foraminal exposure by the removal of the lateral aspect of the pars interarticularis may be able to diminish the inadequate decompression and traction of the nerve structures; however, it may lead to increase stress and fracture of the neural arch. Methods We used 15 human cadaver L3 and L4 lumbar vertebrae for measuring the thickness of the pars interarticularis. The ventral and dorsal surfaces were subdivided into 4 equal parts, and the thickness of each part was measured using a digital caliper. An experimentally validated 3-dimensional nonlinear finite element model of the intact L3-S1 segment was used to simulate the lateral removal of one fourth and one half of the L3 and L4 pars interarticularis. Results The mean thicknesses of the pars interarticularis showed a gradual increase toward the lateral edge. Finite element model analyses predicted stresses increased to 35% and 40% after removal of one half of the lateral part of the L3 and L4 pars interarticularis, respectively, and were much closer to the intact spine after removal of one fourth of the lateral part of the pars interarticularis. Conclusion The removal of one fourth of the lateral aspect of the pars interarticularis has minimal influence on the stresses in the remaining L3 and L4 neural arches. The lateral half of the pars has the largest thickness, and its removal leads to considerable stress increases.