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In this paper, a numerical model of tracked vehicle with a simplified suspension and a winch forcing movement at a constant speed of 2 m / s is presented. The simplified vehicle body was created in the CAD environment, the suspension model, dry and wet obstacle, as well as the winch system and material models, were created in the LS PREPOST. The body of the vehicle was treated as a rigid, mounted by springs and dampers on tracks, the solid element was replaced by a shell element with assigned moments of inertia and mass in the node located in the centre of gravity of the vehicle. The characteristics of the resultant contact force of vehicle travel on the rigid ground for a dry and water obstacle are presented.

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In this paper, a new methodology for the numerical simulation of the wheel–surface interaction has been presented. The finite-element method was combined with the discrete-element method, rigid body dynamics, and the advanced wheel–surface friction model. Compared to the current state-of-the-art, this novel approach can more realistically model the application of the traction force on the contact surface between the wheel and the soil. The rotation of a non-driven wheel is caused by the movement of the axis and the contact forces. The method that has been developed is able to assess both the longitudinal and lateral forces for a wide range of attack angles of the wheel; this is essential for calculating the traction effort of skid-steered vehicles. [ABSTRACT FROM AUTHOR]

We developed an adiabatic theory for cold anisotropic collisions between slow atoms and cold molecules. It enables us to investigate the importance of the couplings between the projection states of the rotational motion of the atom about the molecular axis of the diatom. We tested our theory using the recent results from the Penning ionization reaction experiment 4He(1s2s ³S) + HD(1s²) 4He(1s²) + HD+(1s) + e- [Lavert-Ofir et al., Nat. Chem. 6, 332 (2014)] and demonstrated that the couplings have strong effect on positions of shape resonances. The theory we derived provides cross sections which are in a very good agreement with the experimental findings. [ABSTRACT FROM AUTHOR]

The absorption spectra of the cold Na2 molecule dressed by a linearly polarized standing laser wave is investigated with a theoretical model incorporating translational, electronic, vibrational as well as rotational degrees of freedom. In such a situation a light-induced conical intersection (LICI) can be formed (J. Phys. B: At. Mol. Opt. Phys., 2008, 41, 221001). To measure the spectra a weak field is used whose propagation direction is perpendicular to the direction of the dressing field but has identical polarization direction. Although LICIs are present in our model, the simulations demonstrate a very robust absorption spectrum, which is insensitive to the intensity and the wavelength of the dressing field and which does not reflect clear signatures of light-induced nonadiabatic phenomena related to the strong mixing between the electronic, vibrational, rotational and translational motions. However, by widening artificially the very narrow translational energy level gaps, the fingerprint of the LICI appears to some extent in the spectrum. [ABSTRACT FROM AUTHOR]

This paper presents a water-level control system in a drum boiler. The system was equipped with a fault tolerant control-type diagnostic system. The paper presents the results of tests conducted on the fault tolerant control system implemented in the water-level control system in a boiler drum. The diagnostics of the measurement circuits was carried out online. To that end, the appropriate partial models were developed and tested. This allowed for the application of analytical redundancy for the measurement circuits. The paper also identifies the influence of diagnostics and fault tolerance on the values of reliability indices and operating safety of a power unit. Fault tolerant control systems increase the safety of a power unit operation, and the studies described in the paper directly contribute to them. These kinds of systems have not been used so far in power unit automation. Site tests confirmed the validity of the acquired concept for the diagnostic system. Fault tolerant control systems have not been commonly applied in power engineering yet. Studies of the water-level control system in a steam drum using the fault tolerant control system for the measurement circuits as presented in the paper are original ideas, providing a new solution. All control systems made for the study fulfil their role in a satisfactory way, which results in a minor deviation in the water-level adjustment in the boiler drum. The tests confirmed the efficiency of the fault detection algorithm. The created models of the water level and flows proved to be successful. Under a no-fault condition of the facility, there were no errors in the diagnoses and the values of all residua were below the detection thresholds. This was achieved despite a high value of measurement noises. The residua helped detect minor faults. [ABSTRACT FROM AUTHOR]

We recently developed an adiabatic theory for cold molecular collision experiments. In our previous application of this theory (Pawlak, M.; et al. J. Chem. Phys. 2015, 143, 074114), we assumed that during the experiment the collision of an atom with a diatom takes place when the diatom is in the ground rotational state and is located in a plane. In this paper, we present how the variational approach of the adiabatic theory for low-temperature collision experiments can be used for the study a 5D collision between the atom and the diatomic molecule with no limitations on its rotational quantum states and no plane restrictions. Moreover, we show here the dramatic differences in the measured reaction rates of He(23S1) + ortho/para-H2 → He(1s2) + ortho/para-H2 + + e- resulting from the anisotropic long-range interactions in the reaction. In collisions of metastable helium with molecular hydrogen in the ground rotational state, the isotropic potential term dominates the dynamics. When the collision is with molecular hydrogen in the first excited rotational state, the nonisotropic interactions play an important role in the dynamics. The agreement of our results with the latest experimental findings (Klein A.; et al. Nat. Phys. 2017, 13, 35-38) is very good. [ABSTRACT FROM AUTHOR]

Molecular-type systems, (m1)�(m2)�(m3)∓, consisting of three particles of masses mi and of unit electric charges with the Coulomb interactions weakened by the Debye screening are considered. Existence and range of Borromean binding in symmetric systems (of masses m1 = m2) is investigated with respect to the masses of their constituents. It is shown that such systems can exist in Borromean ground states if the mass ratio q = m3/m1 is less or equal to 1.668. This improves considerably the lower bound to the limit of existence of the Borromean binding of symmetric systems suggested by Pont and Serra (2009 Phys. Rev. A 79 032508) as q ⩽ 1. Qualitative meaning of the improvement is that the Borromean binding occurs not only for systems where two identical particles are heavier than the third one but it is also possible for systems of the opposite mass relation. The range of screening parameter in which a system is Borromean known as a Borromean window is also determined for μ+μ+e−, π+π+μ−, π+μ−μ− and e+e−e−. [ABSTRACT FROM AUTHOR]

3D printing of a composite structure with shape memory materials requires a special approach to the subject, at the stage of the design and printing process. This paper presents the design steps during the development of a 3D-printed composite structure with shape memory material. The connection points between the SMA fibers and the printer filament are developed in the MATLAB environment. Finite element method is used to simulate the shortening of the shape memory material under the influence of temperature and its effect on the printed polymer material is presented. In the MATLAB environment, evolutionary algorithms were used to determine the shape of the SMA fiber alignment. This work demonstrates the use of shape memory effect in 3D printed smart composite structures, where the component takes a predetermined shape. The structure obtained as a result of such printing changes with the heat generated by the current voltage, making it the desired fourth dimension. [ABSTRACT FROM AUTHOR]

Purpose: To compare 5 × 5 Gy preoperative radiotherapy with immediate surgery vs. preoperative chemoradiotherapy (50.4 Gy, 5-fluorouracil, leucovorin) with delayed surgery in a randomized trial for cT3-T4 low-lying rectal cancer. Despite the downstaging effect of chemoradiotherapy, similar long-term outcomes were observed in both groups. Methods: The Cox model was used to evaluate the prognostic value of ypTN (“yp” denotes that pathologic classification was performed after initial multimodality therapy) categories and the surgical margin status in 291 patients. Results: Disease-free survival (DFS) (hazard ratio [HR] 1.05, 95% confidence interval [CI], 0.73–1.51), distant metastases (HR, 1.17; 95% CI, 0.77–1.78), and local control (HR, 1.45; 95% CI, 0.74–2.84) were similar in both arms. The ypN status was the only independent prognostic factor for DFS (p < 0.001). An interaction (p = 0.016) between N stage and the assigned treatment was demonstrated. For ypN-negative patients, DFS was similar in both arms (HR, 0.83, 95% CI, 0.47–1.48); however, for ypN-positive patients, DFS was worse in the chemoradiotherapy arm (HR, 1.73; 95% CI, 1.07–2.77). The 4-year (median follow-up) DFS rate in N-positive patients was 51% in the 5 × 5-Gy arm vs. 25% in the chemoradiotherapy arm. The corresponding 4-year rates for the incidence of local recurrence and distant metastases were 14% vs. 27% (HR, 1.95; 95% CI, 0.78–4.86) and 38% vs. 68% (HR, 2.05; 95% CI, 1.21–3.48). Conclusion: N-positive disease after chemoradiotherapy indicates radiochemoresistance. N-positive disease after 5 × 5 Gy RT includes both radiosensitive and radioresistant tumors, because the interval between radiotherapy and surgery was too short for radiosensitive cancer to undergo necrosis. Thus, the greater risk of distant metastases recorded in the chemoradiotherapy arm suggests that radiochemoresistance of nodal metastases from rectal cancer is associated with a high potential for developing distant metastases. [Copyright &y& Elsevier]

We present a simple expression and its derivation for reaction rate coefficients for cold anisotropic collision experiments based on adiabatic variational theory and time-independent non-Hermitian scattering theory. We demonstrate that only the eigenenergies of the resulting one-dimensional Schrödinger equation for different complex adiabats are required. The expression is applied to calculate the Penning ionization rate coefficients of an excited metastable helium atom with molecular hydrogen in an energy range spanning from hundreds of kelvins down to the millikelvin regime. Except for trivial quantities like the masses of the nuclei and the bond length of the diatomic molecule participating in the collision, one needs as input data only the complex potential energy surface (CPES). In calculations, we used recently obtained ab initio CPES by D. Bhattacharya et al. ( J. Chem. Theory Comput. 2017 , 13 , 1682 - 1690 ) without fitting parameters. The results show good accord with current measurements ( Nat. Phys. 2017 , 13 , 35 - 38 ).

Resonances are metastable states that decay after a finite period of time. These states play a role in many physical processes. For example, in recent cold collision experiments, autoionization from a resonance state was observed. Complementing such observations with theory provides insight into the reaction dynamics under study. Theoretical investigation of autoionization processes is enabled via complex potential energy surfaces (CPESs), where the real and imaginary parts, respectively, provide the energy and decay rate of the system. Unfortunately, calculation of ab initio polyatomic CPESs are cumbersome; hence, they are not in abundance. Here, we present an ab initio polyatomic CPES utilizing a recently developed approach, which makes such calculations feasible. This CPES helps interpret the autoionization process observed in the He(2 3 S) + H 2 collision. From the behavior of the calculated CPES we can conclusively determine the nature of the autoionization process. Moreover, this CPES was used to generate reaction rates for the collision of He with ortho- and para-H 2 . These reaction rates are obtained from first principles. The results show a remarkable agreement with the cold collision experimental measurements, which demonstrates the robustness of our method. Hereby, we provide a computational tool for designing and interpreting new types of experiments that involve resonance states, e.g., in nucleobase damages (DNA or RNA) or in interatomic (intermolecular) Coulombic decay.

Unlabelled: Infectious complications and their consequences are still key issues in rectal cancer surgery. Currently, intravenous antibiotic administration is a recognized method for lowering the rate of these complications. The aim of the study was to assess the efficacy of complementary application of a gentamicin-impregnated sponge in the perineal wound or in the vicinity of intestinal anastomosis after abdominoperineal resection or low anterior resection., Material and Methods: 112 patients with primary rectal cancer were enrolled in this study. 42 patients were treated with a gentamicin sponge and drainage (group A) and 70 individuals were treated with drainage alone (group B). In the aforementioned groups a routine short-term regimen of antibiotic prophylaxis was used. We applied gentamicin-impregnated sponges in 27 patients in whom anterior resection was performed and in 15 patients from the abdominoperineal resection group (64% and 36%, respectively). In the control group, 44 anterior resections and 26 abdominoperineal resections were carried out (63% and 37%, respectively)., Results: We did not observe statistically significant differences in the incidence of suppurative complications (intraabdominal abscess, perineal wound infection): 4 cases (9.52%) in group A and 9 (12.58%) in group B and anastomotic leakage with clinical manifestation after low anterior resection: 1 case (3.7%) in group A and 2 (4.5%) in group B. Postoperative fever of unknown origin was noted more often in group B: 23 patients (32.8%) versus 10 patients (23.8%) in group A and this difference was statistically significant (p<0.05). Hospitalization after surgery was also significantly longer in group B (9-37 days, median 11 days) as compared with group A (8-26 days, median 13 days) (p<0.05)., Conclusions: Local antibiotic therapy in rectal cancer surgery lowered the incidence of postoperative fever of unknown origin and permitted shorter hospitalization after surgery. Local gentamicin application in rectal cancer surgery did not change significantly the rate of infectious complications.

Unlabelled: The aim of the study was to assess the impact of hospital caseload on long-term outcomes of rectal cancer patients. We posed two questions: 1. Does the number of operations carried out in the surgical department influence five year survival and local recurrence rates? 2. Does surgery alone without adjuvant therapy performed in the particular department affect long-term results?, Material and Methods: 215 consecutive rectal cancer patients treated in six hospitals of the Łódź district between 1994 and 1998 were enrolled into this prospective study. We analyzed patients in whom local excision, low anterior resection, abdominoperineal resection and Hartmann's procedure were performed. 27 percent of patients received adjuvant therapy such as radio- or chemotherapy or both. Long-term results were compared between high and low volume institutions by means of local recurrence and five year survival rates., Results: In high volume departments; 69.2% of five year survival rates were obtained versus 46.6% for low volume institutions (p=0.00433). Similar differences were noted comparing local recurrence rates between the aforementioned groups: 19.7% versus 36.5%, respectively (p=0.00430). In surgically treated patients who did not receive adjuvant therapy statistically significant differences were found: 76.5% of patients operated on in high volume hospitals survived five years as compared with 42.9% for low caseload institutions (p=0.00013). Local recurrence rates were 15.5% for high caseload institutions and 38.5% for low caseload hospitals (p=0.00042)., Conclusions: High volume hospitals achieved better results in rectal cancer patients with regard to five year survival and local recurrence rates. Better outcomes were also obtained in high caseload departments regarding surgically treated patients who did not receive adjuvant therapy.