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This experiment aimed to ascertain whether adding chitosan-oligosaccharides (COS) to the diet will affect Mandarah laying hens’ productivity and reproductive efficiency. At the age of 34 weeks, 120 laying hens and 12 cocks of the Mandarah chicken strain were separated into four groups, each consisting of 30 hens and three cocks. The 1st group served as a control group, receiving only a basic diet. The 2nd, 3rd, and 4th experimental groups received 0.1, 0.2, and 0.5 g/kg of chitosan-oligosaccharides as an addition to the base diet, respectively. According to the findings of this study, the majority of the analyzed attributes differed significantly between treatment groups. Comparing the COS-treated birds to the control birds, the COS-treated birds significantly increased egg production, improved feed conversion, Haugh unit score, shell thickness, fertility, hatchability, ovary weight, and the number of yellow ovarian follicles as well as blood estradiol-17β (E2) and testosterone concentrations. Furthermore, compared to the other treated groups, introducing COS at a level of 0.1 g/kg diet resulted in the best laying rate, egg mass, and feed conversion. The highest percentage of fertility, hatchability of hatching eggs, ovary weight, number of yellow ovarian follicles, and serum E2 concentration was also found in birds fed COS at a dose of 0.2 g/kg feed. In addition, compared to the control diet, COS treatment at 0.1, 0.2, and 0.5 g/kg enhanced relative economic efficiency by 464.43, 457.41, and 352.75%, respectively. It is concluded that chitosan improves economic efficiency, reproductive performance, productivity in laying hens, and overall health when used at 0.1 g/kg diet.

Even though bismuth telluride is frequently produced by mechanical alloying for thermoelectric materials, no data has been published addressing the thermal behavior and activation energy of the milled n-type Bi2Te2.7Se0.3powders. This paper studies the activation energy of grain growth for the nanocrystalline n-type Bi2Te2.7Se0.3and two graphene-Bi2Te2.7Se0.3composites with different graphene concentrations (0.05 and 0.5 wt.%). Grain size and structural analyses of these samples have been carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal stability of the three samples is investigated by incorporating differential scanning calorimetry data with the Kissinger model. The activation energy of the pristine Bi2Te2.7Se0.3alloy is found to be 268 kJ/mol. For the composite samples, a lower graphene weight percentage (0.05 wt.%) increased the activation energy to 270 kJ/mol. In contrast, higher amounts of graphene (0.5 wt.%) reduced the activation energy significantly to 254 kJ/mol. The observed effect is found to be directly related to graphene’s exfoliation in the bismuth telluride matrix. These results offer a better understanding of the thermal behavior of the nanocrystalline pristine n-type Bi2Te2.7Se0.3and the influence of graphene nanofiller on the thermal stability of the bismuth telluride nanocomposites.

The state-of-the-art Bismuth-Telluride (Bi2Te3) based systems are promising thermoelectric materials for efficient thermoelectric applications. In this study, the effect of graphene nanosheets (GNS) integrity on thermoelectric properties of a p-type Bi0.4Sb1.6Te3alloy has been studied using high-energy ball milling and SPS sintering techniques. The synthesized pristine Bi0.4Sb1.6Te3and 0.05wt% GNS/Bi0.4Sb1.6Te3nanocomposites at different addition times of GNS have exhibited a single-phase and artifact-free bulk nanocrystalline Bi0.4Sb1.6Te3with nanocrystals size of 17 nm. The TEM analysis confirmed the mechanical exfoliation of graphene filler in 5m nanocomposite into a single-layered nanostructure with an interplanar spacing of 0.343 nm. The prominent Raman features of the monolayered graphene sheet have appeared in the synthesized 5m-GNS/Bi0.4Sb1.6Te3nanocomposite. This highlighted the crucial rule of graphene addition time on its structure and morphology of the synthesized nanocomposites. The ZT profile of 5m nanocomposite reached 0.801 at 348 K till 398 K. This resulted in 65% of improvements to the pristine Bi0.4Sb1.6Te3pellet at 323 K. The obtained results were used to simulate a thermoelectric (TE) device module using ANSYS Workbench. The GNS nanocomposites have shown an ultrahigh output power of 95.57 W compared to 89.96 W for the pristine module at ΔT of 150 °C. The GNS addition has increased the output power of pristine Bi0.4Sb1.6Te3by 7%, leading to comparable TE performance to other simulated Bi2Te3systems.

Caenorhabditis elegans (C. elegans) is an optically transparent nematode that shares many gene orthologs and homologs with humans. C. elegans are widely used in large populations for genetic studies relevant to human biology and disease. Success of such studies frequently relies on the ability to image C. elegans structure at high-resolution and high-speed. In this manuscript, we report on the feasibility and suitability of a high-speed variant of reflectance confocal microscopy, known as spectrally encoded confocal microscopy (SECM), for label-free imaging of C. elegans. The developed system utilizes near-infrared illumination in conjunction with refractive and diffractive optics to instantaneously image a confocal image line at a speed of up to 147 kHz with lateral and axial resolutions of 2µm and 10µm, respectively. Our imaging results from wild-type C. elegans and four mutant strains (MT2124, MT1082, CB61, and CB648) demonstrate the ability of SECM in revealing the overall geometry, key internal organs, and mutation-induced structural variations, opening the door for downstream integration of SECM in microfluidic platforms for high throughput structural imaging of C. elegans.

This experiment investigated the influence of different synbiotic processing methods on the intestinal bacterial count, morphology and histological status of developed male Mandarah chicks. Two hundred and ten male Mandarah line chicks aged one day were randomized to receive one of seven chicks. The method and dose for one-time synbiotics administration to the day-old chicks were as follows: G1: chicks on basal diet received no treatment (control); G2: 0.25 ml synbiotics sprayed; G3: 0.50 ml synbiotics sprayed; G4: 0.25 ml of synbiotics are added to drinking water; G5: 0.50 ml of synbiotics are added to drinking water; G6: 0.25 ml of synbiotics dripped into the mouth; and G7: 0.50 ml of synbiotics dripped into mouth drops. Lactic acid bacteria(LAB)were significantly increased (P<0.0001) compared to the control group and other treated groups and had the maximum values after the use of synbiotics via drinking water (0.25 or 0.50 ml). Furthermore, when comparing the treated birds (G4, G5) with the control birds, the Escherichia coliconcentration in the drinking water containing synbiotics was significantly lower. In addition, treated chickens at (G7) showed a higher duodenum, ileum villus height (VH), and VH. - Ileum crypt depth (CD)ratio compared to other groups. In addition, birds treated with 0.50 ml of synbiotics in drinking water (G5) performed better in duodenum, ileum, CD and VH. - CD ratio than the other groups. Meanwhile, intestinal tract length and visceral pH did not differ significantly between groups. It can be concluded that the use of 0.25 ml of synbiotics in drinking water can improve the overall health of birds.

Thermoelectric materials have long been proven to be effective in converting heat energy into electricity and vice versa. Since semiconductors have been used in the thermoelectric field, much work has been done to improve their efficiency. The interrelation between their thermoelectric physical parameters (Seebeck coefficient, electrical conductivity, and thermal conductivity) required special tailoring in order to get the maximum improvement in their performance. Various approaches have been reported in the research for developing thermoelectric performance, including doping and alloying, nanostructuring, and nanocompositing. Among different types of thermoelectric materials, layered chalcogenide materials are unique materials with distinctive properties. They have low self-thermal conductivity, and their layered structure allows them to be modified easily to improve their thermoelectric performance. In this review, basic knowledge of thermoelectric concepts and challenges for enhancing the figure of merit is provided. It discusses briefly different groups of layered chalcogenide thermoelectric materials with their structure and thermoelectric properties. It also reports different approaches in the literature for improving their performance and the recent progress done in this field. It highlights graphene as a promising nano additive to layered chalcogenide materials’ matrix and shows its effect on enhancing their figure of merit.

This paper provides a critical review on the current status of graphene-reinforced metal matrix composites (GRMMCs) in an effort to guide future work on this topic. Metal matrix composites are preferred over other types of composites for their ability to meet engineering and structural demands. Graphene is considered an ideal reinforcement material for composites due to its unique structure and extraordinary physical, thermal, and electrical properties. Incorporating graphene as a reinforcement in metals is a way of harnessing its extraordinary properties, resulting in an enhanced metallic behavior for a wide variety of applications. Combining graphene with bulk metal matrices is a recent endeavor that has proven to have merit. A systematic study is needed to critically examine the efforts applied in this field, the successes achieved, and the challenges faced. This review highlights the three main pillars of GRMMCs: synthesis, structure, and properties. First, it discusses the synthesis techniques utilized for the fabrication of GRMMCs. Then, it highlights the resulting microstructures of the composites, including graphene dispersion and interfacial interactions. Finally, it summarizes the enhancements in the mechanical, electrical, thermal, and tribological properties of GRMMCs, while highlighting the effects of graphene type and content on those enhancements.

This study aimed to determine the influence of dietary mannan-oligosaccharides (MOS) on the immune system, hematological traits, blood biochemical parameters, and histological state of laying hens. At 34 wk of age, The Mandarah chicken strain's 120 laying hens and 12 cocks were divided into 4 groups, each with 30 hens and 3 cocks. The first group performed as a control group, which nourished on a basal diet. The second, third, and fourth experimental groups received 0.1, 0.2, and 0.5 g/kg of MOS and a base diet, respectively. Birds obtained MOS at numerous doses significantly (P˂ 0.05) raised serum levels of immunoglobulin Y (IgY), immunoglobulin M (IgM), and avian influenza (AI) antibodies compared to control birds. Furthermore, adding MOS at a level of 0.1 g/kg diet significantly improved the immune response of the control group. Additionally, compared to the control group, treated birds with MOS at various dosages did not significantly enhance hematological parameters such as red blood cells (RBCs), white blood cells (WBCs), hemoglobin, and hematocrit. Compared to control birds, birds fed MOS at all levels exhibited considerably lower serum cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) values. Also, compared to other treated birds, MOS-treated birds displayed improved histological examination of the small intestine, isthmus, and testis compared to the control group, particularly in birds fed MOS at 0.1 and 0.2 g/kg diet. It could be concluded that using MOS at 0.1 or 2 g/kg diet can successfully improve the physiological performance and overall health of laying hens.

This experiment aimed to examine the effect of chitosan-oligosaccharides (COS) supplementation in laying hens' diets affected their immune response, hematological characteristics, blood biochemical parameters, and histological status. At the age of 34 wk, 200 laying hens and 20 cocks of the Mandarah chicken strain were allotted into four groups, each consisting of 50 hens and five cocks. The first group acted as a control group, fed on a basal diet. The second, third, and fourth experimental groups each received 0.1, 0.2, and 0.5 g/kg of COS in addition to a base diet. Birds received COS at various dosages had significantly (P˂ 0.05) increased serum concentration of immunoglobulins, avian influenza, and Newcastle disease antibodies compared with the control birds. Moreover, adding COS at level 0.2 g/kg diet insignificantly enhanced immune response than the rest of the treatment groups. Also, treated birds with COS at different levels had insignificantly improved hematological parameters such as red blood cells, white blood cells, hemoglobin and hematocrit compared to the control group. Birds fed COS at all levels had significantly decreased serum cholesterol, triglycerides, Ca++and alanine aminotransferase concentrations compared with control birds. In addition, compared to the control group, chitosan-treated birds showed enhanced histological examination of the small intestine, isthmus, and testis, notably in birds given COS at 0.1 g/kg diet compared to other treated birds. Cocks fed COS at all levels improved testicular tissues and increased the number and diameter of seminiferous tubules compared with control birds Morphological examination of the ileum showed increased villi number, height, and crypt depth. It is possible to conclude that laying hens' physiological performance and general health can be effectively improved by using chitosan at 0.1 or 2 g/kg diet levels enhanced immune response.

Currently, permanent vascular stents are fabricated using titanium and stainless steel implants that are nondegradable and offer high stability, but they have certain disadvantages. For example, the prolonged exposition of aggressive ions in the physiological media and the existence of defects in the oxide film create conditions for corrosion to occur, thus triggering unwanted biological events and compromising the mechanical integrity of the implants. Moreover, when the implant does not need to be permanent, there is the need to submit the patient for a second surgery for implant removal. As a solution for nonpermanent implants, biodegradable magnesium alloys have been deemed a promising substitute, for example, for cardiovascular-related applications and the construction of orthopedic devices. A biodegradable magnesium alloy (Mg–2.5Zn) reinforced by zinc and eggshell was employed in this study as an environment-conscious magnesium (eco) composite (Mg–2.5Zn–xES). Disintegrated melt deposition (DMD) was used to fabricate the composite. Experimental studies were conducted to investigate the biodegradation performance of Mg–Zn alloys containing 3 and 7 wt % eggshell (ES) in simulated body fluid (SBF) at 37 °C. Different corrosion techniques were used to study the corrosion behavior of the Mg–2.5Zn–xES composites, including weight loss measurements, hydrogen evolution, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning vibrating electrode technique (SVET). Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were employed to scrutinize the corroded surfaces’ morphology and composition. The outcomes indicated that Mg–2.5Zn–3ES possesses the lowest degradation activity.

MoS2Nanoflowers Scanning electron microscopy of hydrothermally synthesized MoS2reveals a morphology well‐described by nanoflowers (see article number 2200393by Carla Bittencourt and colleagues). Chemical analysis of the nanoflowers shows the presence of 2H‐MoS2and MoOx, the excess of oxygen atoms being detrimental to electronic and optical properties. Ion irradiation can be used for changing the stoichiometry of the material. Irradiating the nanoflowers using low‐kinetic energy hydrogen ions decreases the relative oxygen amount, whereas the photoluminescence intensity observed at 1.71 eV is increased.

The influence of low kinetic energy hydrogen ion irradiation on the chemical composition and luminescence intensity of MoS2nanoflowers (NFs) hydrothermally synthesized is reported. X‐ray photoelectron spectroscopy (XPS) core‐level analysis of the as‐synthesized MoS2NFs reveals the presence of the 2H‐MoS2(semiconductor) crystal phase and MoOx. Furthermore, the relative amounts of oxygen and potassium decrease for increasing hydrogen ion irradiation time, whereas the photoluminescence (PL) intensity observed at 1.71 eV increased approximately three times. Chemical analysis of hydrothermally synthesized MoS2nanoflowers (NFs) shows the presence of 2H‐MoS2and MoOx. The NFs are irradiated using low‐kinetic energy hydrogen ions. The relative oxygen amount decreases with increasing hydrogen ion irradiation time, whereas the photoluminescence (PL) intensity observed at 1.71 eV increases approximately three times.

In this study, we compare the thermoelectric properties of coarse-grained n-type Bi2Te2.55Se0.45alloy prepared by induction melting with the bulk-nanostructured prepared by ball milling and hot-pressing techniques. The corresponding thermoelectric properties showed different behavior for each material processed using different routes. The most striking result of the study is observing a p-type behavior and charge carrier transition from p-to n-type for the coarse-grained alloy. These observed phenomena are related mainly to the unique needle-like microstructure accompanied by high lattice strain. Lastly, the obtained figure-of-merit values for the coarse needle-like structure and bulk nanostructured Bi2Te2.55Se0.45alloys are 0.20 and 0.80 at their optimum temperatures of 60 and 120 °C, respectively.

Spatial cognition is a pivotal consideration in hospital buildings. Potential circulation configuration alternatives in hospitals have been filtered to 59 significant alternatives, to be simulated using space syntax analyses for measuring connectivity, visual integration, and visual step depth. Best alternatives have been determined via comparison and correlation analysis. A survey has been conducted, comparing the preferences of professional architects with simulation outcomes. Results show that best and worst alternatives exist in triangular and circular buildings, respectively. Also, cul-de-sac corridors are argued to promote spatial cognition better than looped corridors. Notably, cognition is inversely proportional to the curvature of the circulation spaces, number of nodes, and the number of branches. The survey showed a weak perception of the best alternatives, while respondents have a better perception of highly visible locations in these alternatives.

Located in the north-western of Saudi Arabia, Taima is an ancient town inhabited since the Bronze Age. Scholarly interest has begun since the late 19th Century, providing systematic recording of archaeological remains. Since the beginning of the 20th Century, most published researches focused on the archaeology of ancient sites in and around Taima.

The process of developing a knowledge city requires active participation of the entire society. Universities have managed to be the agents of change and economic growth. The local government has been the body responsible for the exchange, evaluation, and update of knowledge. KCs initiatives are compiled by the private sector, stimulating community leaders to set ambitious goals. Further, knowledge citizens have played a vital role via the participation in the creation, exchange and transformation of knowledge. In this paper, a collaboration model to restructure the interrelationship of knowledge agents in the City of Jeddah is sketched out, moving a step towards bridging the gap between theory and application. Different roles of knowledge agents are identified and reviewed. Further, various knowledge cycle models are analysed and examined. The local context of the City of Jeddah is introduced, guidelines are derived at and a collaboration model is sketched out.

The thermal stability of polycrystalline tin selenide (SnSe) is essential for its long-term applications. In this study, the thermo-mechanical stability of hot compacted polycrystalline SnSe and SnSe/graphene nanocomposite is evaluated. All samples were prepared using a combination of mechanical alloying and hot compaction under an argon atmosphere. A severe bloating behavior was observed in the pristine SnSe hot compacted disks after post densification annealing. Consequently, these disks exhibited volume expansion and a drop in density, resulting in the formation of pores and cracks within the sample, which significantly degraded the electrical performance with consecutive thermal cycling. Interestingly, the bloating behavior was reduced upon the incorporation of graphene within the SnSe matrix. However, this reduction was limited to samples with a homogeneous distribution of graphene. Dilatometer measurements showed that the as-compacted SnSe/graphene nanoplatelets (GNP) sample in which graphene was milled for 4 h exhibited less hysteresis than the pristine SnSe sample. Accordingly, the electrical performance of the SnSe/GNP samples was more stable than the pristine SnSe after consecutive thermal cycles. The obtained results indicate that homogeneously distributed graphene plays a significant role in improving the thermal stability of the SnSe-based nanocomposite.

Abstract

Nanoindentation was used to measure the mechanical properties of 200mm diameter (100) CZ Si wafers subjected to the initiation and propagation of micro-crack defects. Silicon amorphization and phase changes were observed and accompanied by a monotonic decrease in hardness and elastic modulus, as the nanoindent tip approached the micro-crack shank or point. Identification and profiling of these localized phase transitions was obtained in the vicinity of the micro-cracks using electron back-scattered diffraction (EBSD) and Raman spectroscopy. It was found that the amorphous Si regions extend for about 10 µm at the edges and ahead of a moving crack tip. Wafers from ingots grown at faster growth rates with enhanced thermal gradients and associated point defect/impurity produce large localized stresses in the wafer core, which are capable of changing the path of propagating cracks. FTIR and Raman spectroscopy analysis were used to quantify local stresses due to radial oxygen precipitate variations. The resulting stress modified crack deviates considerably from energetically favorable [110]/(111) directions, following a radial path suggesting a ductile fracture failure mode.

We report on crack propagation in CZ silicon wafers grown for photovoltaic (PV) applications at faster growth rates than those typical for 200 mm diameter ingots. Enhanced thermal gradients and point defect/impurity distributions associated with rapid growth produces large localized stresses in the wafer core which impacts the direction of propagating cracks. The stress modified crack behavior deviates considerably from the energetically favorable Si[110]/(111) systems enabling scenarios that behave like a ductile fracture following a radial path. Minority carrier lifetime mapping and microscopic etch pit measurements confirmed the presence of a series of radial oxygen precipitate (OP) rings, which impact the energy transfer process at the expanding crack-tip, thereby modifying the crack stress path. Raman spectroscopy was used to quantify the local stresses due to radial oxygen precipitate variations, whereas TEM studies confirmed the presence of OP's, their influence on defect generation and probable role on crack path deviation.

This paper documents the approach, methodology and outcomes of the knowledge cities (KCs) ‘open design studio’ (ODS) model, which allowed for the interaction of the three planning and design disciplines in the Faculty of Environmental Design at King Abdul-Aziz University. The ‘ODS’ methodology relied on the ability of each discipline to create its own approach to the study; working under one roof, allowing for ongoing exchange of knowledge and findings, and calling for periodical formal joint presentations to align the work of all tracks. First, the rational motives behind the adoption of the subject area, the selection of the case study, the utilisation of educational projects as a tool, and the promotion of multi-disciplinary design studio as a work environment were introduced. Next, the formation of the ODS, the development model, activities, and outcomes were presented. Lastly, a discussion highlighting the achievements, challenges and directions for future developments took place.

Nanoindentation was used to stimulate and measure materials processes which occur during the initiation and propagation of micro-crack defects in monocrystalline (100) Si wafers. Silicon amorphization occurs and is accompanied by a monotonic drop in hardness and elastic modulus as the nanoindents approach the micro-crack shank or tip. Identification and profiling of localized phase transitions were obtained in the vicinity of a micro-crack using electron back-scattered diffraction (EBSD) and Raman spectroscopy and indicate that regions of amorphous Si extend for about 10 um at the edges and ahead of a moving crack tip.

In this study, we have used a single nanoindentation probe to simultaneously examine the deformation behavior and electrical properties of both mono- and multi-crystalline PV silicon. During nanoindentation loading and unloading cycles, various pressure induced phase transformations occur both under and in the vicinity of the indentation tip. These phase transformations can be monitored in-situ via signature "pop-in" and "pop-out" events that occur in both electrical I-V and physical indent displacement curves. These events are a function of the Si chemistry, structure, and orientation, which we have examined via simultaneous measurements through a conductive nanoprobe, along with complementary spectroscopic Raman analysis.

In teaching architectural design, schools have various perspectives concerning the projects taught in design studios. Some argue that students should challenge real design problems: the real project (RP) approach. Others claim that applying hypothetical projects could be more viable if they fit within the teaching protocol: the instructed protocol (IP) approach. Based on observations and a field survey comparing the RP approach, applied in Kunstuniversitat-Linz, Austria, and the IP approach, applied in Assiut University, Egypt, it was argued that both approaches have advantages and disadvantages. To reach a compromise, a teaching profile called the instructed protocol real projects (IPRP) profile was proposed. The profile has two components: an instructed teaching protocol and four different scenarios for proposing educational design projects.

This paper reviews a method, “in situ consolidation ball milling” that provides artifactfree bulk nanocrystalline samples for several ductile metals such as Zn, Al and Al alloys, and Cu and Cu alloys. The preparation method is described in this paper and examples of the mechanical behavior of nanocrystalline materials made by this technique are given. It is found that in such artifact-free metals, combinations of both high strength and good ductility are possible.

The best way of reducing roll motion is by increasing roll damping. Bilge keels are the most common devices for increasing roll damping. If more control is required, anti-roll tanks and fins are used. Tanks have the advantage of being able to function when the ship is not underway. Our objective is to develop design procedures for passive tanks for roll reduction in rough seas. This paper focuses on the design of passive U-tube tanks. The tank-liquid equation of motion is integrated simultaneously with the six-degree-of-freedom (6DOF) equations of the ship motion. The coupled set of equations is solved by using the Large Amplitude Motion Program ‘LAMP’, which is a three-dimensional time-domain simulation of the motion of ships in waves. The unstabilized and stabilized roll motions of a S60-70 ship with forward speed and beam waves have been analyzed. For high-amplitude waves, the unstabilized roll angle exhibits typical nonlinear phenomena: a shift in the resonance frequency, multi-valued responses, and jumps. The performance of a S60-70 ship with a passive tank is investigated in various sea states with different encounter wave directions. It is found that passive anti-roll tanks tuned in the linear or nonlinear ranges are very effective in reducing the roll motion in the nonlinear range. The effect of the tank damping, frequency, and mass on the tank performance is studied. Also, it is found that passive anti-roll tanks are very effective in reducing the roll motion for ships having a pitch frequency that is nearly twice the roll frequency in sea states 5 and 6.

Experiments performed in actively proliferating plant cells both in space and simulated microgravity have evidenced a common effect: cell proliferation appears enhanced whereas cell growth is depleted. Coordination of cell growth and proliferation, called meristematic competence, is a major feature of meristematic cells and its disruption may lead to important alterations in the developmental pattern of the plant. Auxin is known to be a mediator of the transduction of the gravitropic signal and a regulator of the rates of growth and proliferation in meristematic cells, as well as of their further differentiation. Therefore, gravity sensing, gravitropism, auxin levels, and meristematic competence are mutually interrelated. However, our experiments in simulated microgravity, using both mechanical and magnetic levitation technologies, have revealed that this interdependence is neither strict nor univocal and may include additional factors and mechanisms. Available data indicate that altered gravity may affect cell growth and proliferation by mechanisms alternative to the transduction of the gravitropic signal perceived by columella cells in the root tip. These mechanisms would include gravity sensing independent from statolith displacement and transduction mediators other than polar auxin transport.

We report on crack propagation in CZ silicon wafers grown for photovoltaic (PV) applications at faster growth rates than those typical for 200 mm diameter ingots. Enhanced thermal gradients and point defect/impurity distributions associated with rapid growth produces large localized stresses in the wafer core which impacts the direction of propagating cracks. The stress modified crack behavior deviates considerably from the energetically favorable Si[110]/(111) systems enabling scenarios that behave like a ductile fracture following a radial path. Minority carrier lifetime mapping and microscopic etch pit measurements confirmed the presence of a series of radial oxygen precipitate (OP) rings, which impact the energy transfer process at the expanding crack-tip, thereby modifying the crack stress path. Raman spectroscopy was used to quantify the local stresses due to radial oxygen precipitate variations, whereas TEM studies confirmed the presence of OP's, their influence on defect generation and probable role on crack path deviation.

Nanoindentation was used to stimulate and measure materials processes which occur during the initiation and propagation of micro-crack defects in monocrystalline (100) Si wafers. Silicon amorphization occurs and is accompanied by a monotonic drop in hardness and elastic modulus as the nanoindents approach the micro-crack shank or tip. Identification and profiling of localized phase transitions were obtained in the vicinity of a micro-crack using electron back-scattered diffraction (EBSD) and Raman spectroscopy and indicate that regions of amorphous Si extend for about 10 µm at the edges and ahead of a moving crack tip.

In this study, we have used a single nanoindentation probe to simultaneously examine the deformation behavior and electrical properties of both mono- and multi-crystalline PV silicon. During nanoindentation loading and unloading cycles, various pressure induced phase transformations occur both under and in the vicinity of the indentation tip. These phase transformations can be monitored in-situ via signature "pop-in" and "pop-out" events that occur in both electrical I-V and physical indent displacement curves. These events are a function of the Si chemistry, structure, and orientation, which we have examined via simultaneous measurements through a conductive nanoprobe, along with complementary spectroscopic Raman analysis.

We consider a single-stage multiproduct manufacturing facility producing several end-products for delivery to customers with a required customer lead-time. The end-products can be split in two classes: few products with high volume demands and a large number of products with low-volume demands. In order to reduce inventory costs, it seems efficient to produce the high-volume products according to an MTS policy and the low volume products according to an MTO policy. The purpose of this paper is to analyze and compare the impact of the scheduling policy on the overall inventory costs, under customer lead-time service level constraints. We consider two policies: the classical FIFO policy and a priority policy (PR) which gives priority to low volume products over high volume products. We show that for some range of parameters, the PR rule can significantly outperform the FIFO rule. In these ranges, the service level constraints are satisfied by the PR rule with much lower inventory costs.