43 research outputs found

    Thin film solar cells based on the ternary compound Cu2SnS3

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    Alongside with Cu2ZnSnS4 and SnS, the p-type semiconductor Cu2SnS3 also consists of only Earth abundant and low-cost elements and shows comparable opto-electronic properties, with respect to Cu2ZnSnS4 and SnS, making it a promising candidate for photovoltaic applications of the future. In this work, the ternary compound has been produced via the annealing of an electrodeposited precursor in a sulfur and tin sulfide environment. The obtained absorber layer has been structurally investigated by X-ray diffraction and results indicate the crystal structure to be monoclinic. Its optical properties have been measured via photoluminescence, where an asymmetric peak at 0.95 eV has been found. The evaluation of the photoluminescence spectrum indicates a band gap of 0.93 eV which agrees well with the results from the external quantum efficiency. Furthermore, this semiconductor layer has been processed into a photovoltaic device with a power conversion efficiency of 0.54%, a short circuit current of 17.1 mA/cm2, an open circuit voltage of 104 mV hampered by a small shunt resistance, a fill factor of 30.4%, and a maximal external quantum efficiency of just less than 60%. In addition, the potential of this Cu2SnS3 absorber layer for photovoltaic applications is discussed

    High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity

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    The optimal exercise-training characteristics for reducing blood pressure (BP) are unclear. We investigated the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on BP and aortic stiffness in males with overweight or obesity. Twenty-eight participants (18–45 years; BMI: 25–35 kg/m2) performed stationary cycling three times per week for 6 weeks. Participants were randomly allocated (unblinded) to work-matched HIIT (N = 16; 10 × 1-min intervals at 90–100% peak workload) or MICT (N = 12; 30 min at 65–75% peak heart rate). Central (aortic) and peripheral (brachial) BP and aortic stiffness was assessed before and after training. There were no significant group × time interactions for any BP measure (all p > 0.21). HIIT induced moderate reductions in central (systolic/diastolic ∆: −4.6/−3.5 mmHg, effect size d = −0.51/−0.40) and peripheral BP (−5.2/−4 mmHg, d = −0.45/−0.47). MICT induced moderate reductions in diastolic BP only (peripheral: −3.4 mmHg, d = −0.57; central: −3 mmHg, d = −0.50). The magnitude of improvement in BP was strongly negatively correlated with baseline BP (r = −0.66 to −0.78), with stronger correlations observed for HIIT (r = −0.73 to −0.88) compared with MICT (r = −0.43 to −0.61). HIIT was effective for reducing BP (~3–5 mmHg) in the overweight to obese cohort. Exercise training induced positive changes in central (aortic) BP. The BP-lowering effects of exercise training are more prominent in those with higher baseline BP, with stronger correlation in HIIT than MICT

    The effect of high-intensity interval training and moderate-intensity continuous training on aerobic fitness and body composition in males with overweight or obesity: A randomized trial

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    The optimal exercise training characteristics for improving body composition in individuals with obesity are not clear. This study assessed the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on aerobic fitness and body composition in males with overweight or obesity. Twenty-eight participants (18–45 years; BMI: 25–35 kg/m2) performed stationary cycling 3 times per week for 6 weeks. Participants were randomly allocated to work-matched HIIT (N = 16) (10 × 1-min intervals at ~90% peak heart rate) or MICT (N = 12) (30 min at 65–75% peak heart rate). Maximal aerobic capacity (VO2peak) and body composition were assessed before and after 6-week training. Both HIIT and MICT induced moderate increases in aerobic fitness (Δ% VO2peak: HIIT 9 ± 8%, ES = 0.42; MICT: 7 ± 13%, ES = 0.32) and work capacity (Δ% peak workload: HIIT 13 ± 10%, ES = 0.69: MICT 17 ± 15%, ES = 0.76), but these changes did not differ significantly between the groups (all p > 0.16). The effects of HIIT or MICT on body composition outcomes were negligible to small across whole-body and all regional-specific sites (all effect sizes ES = −0.19 to 0.38) and did not differ significantly between the groups (all p > 0.21). Short-term (6-weeks) cycling training did not improve body composition in males with overweight or obesity. Improvements in aerobic fitness were comparable between work-matched HIIT and MICT

    The Tongue Squamous Carcinoma Cell Line Cal27 Primarily Employs Integrin α6β4-Containing Type II Hemidesmosomes for Adhesion Which Contribute to Anticancer Drug Sensitivity

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    Integrins are heterodimeric cell surface glycoproteins used by cells to bind to the extracellular matrix (ECM) and regulate tumor cell proliferation, migration and survival. A causative relationship between integrin expression and resistance to anticancer drugs has been demonstrated in different tumors, including head and neck squamous cell carcinoma. Using a Cal27 tongue squamous cell carcinoma model, we have previously demonstrated that de novo expression of integrin αVβ3 confers resistance to several anticancer drugs (cisplatin, mitomycin C and doxorubicin) through a mechanism involving downregulation of active Src, increased cell migration and invasion. In the integrin αVβ3 expressing Cal27-derived cell clone 2B1, αVβ5 expression was also increased, but unrelated to drug resistance. To identify the integrin adhesion complex (IAC) components that contribute to the changes in Cal27 and 2B1 cell adhesion and anticancer drug resistance, we isolated IACs from both cell lines. Mass spectrometry (MS)-based proteomics analysis indicated that both cell lines preferentially, but not exclusively, use integrin α6β4, which is classically found in hemidesmosomes. The anticancer drug resistant cell clone 2B1 demonstrated an increased level of α6β4 accompanied with increased deposition of a laminin-332-containing ECM. Immunofluorescence and electron microscopy demonstrated the formation of type II hemidesmosomes by both cell types. Furthermore, suppression of α6β4 expression in both lines conferred resistance to anticancer drugs through a mechanism independent of αVβ3, which implies that the cell clone 2B1 would have been even more resistant had the upregulation of α6β4 not occurred. Taken together, our results identify a key role for α6β4-containing type II hemidesmosomes in regulating anticancer drug sensitivity

    Economic justification for the new approach of using videobased smoke detection with the aim of decreasing total costs incurred by the untimely detection of fires on ships

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    Although various methods of using new techniques and technologies in ship fire alarm systems have been developed to date, some of which have made significant improvements in the functioning of such systems, in practice there is still plenty of room for further research regarding the operational efficiency of ship fire alarm systems and its impact on crew, passenger and overall ship safety. The application of electronic and computer technologies enables the development of intelligent solutions to improve the efficiency of ship fire alarm systems. Besides the economic justification, this paper presents a comparative analysis of classical and modern approaches based on video detection and computer vision in the detection of early phase smoke as a precursor to fire incidents. The economic justification of the new approach is concerned with decreasing the costs incurred by the untimely detection of the early stages of fire in ship engine rooms

    Prediction of potential fire hot spots by using a model based on a computerized real-time view with IR cameras on ships

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    One of the key benefits of using thermal imaging is the ability to predict possible fire hazards due to increases in temperature in controlled areas in a particular marine facility or system. This study proposes the possibility of applying new electronic and computer technology as part of a ship’s fire detection system, such as the use of computer vision, using existing marine CCTV systems and installing thermal imaging IR cameras on the same system. It also proposes communication between the CCTV system and the fire detection and central alarm system of a ship. In addition to visual analysis of certain areas on board the ship and the related facilities inside it, with the addition of certain software applications into the existing CCTV system, the system itself becomes a fire alarm system, with the potential to forecast and send early warnings to the ship’s central fire alarm system in real time, thereby contributing to improved safety with regards to various areas, equipment, the ship as a whole, cargo and human lives

    Smaller Representation of Finite State Automata

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    Evaluating oceanographic measurements contributed by citizen scientists in support of Ocean Sampling Day

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    The first Ocean Sampling Day (OSD) took place on June 21, 2014. In a coordinated effort, an internationally distributed group of scientists collected samples from marine surface waters in order to study microbial diversity on a single day with global granularity. Concurrently, citizen scientists enriched the OSD initiative through the MyOSD project, providing additional oceanographic measurements crucial to the contextualization of microbial diversity. Clear protocols, a user-friendly smartphone application, and an online web-form guided citizens in accurate data acquisition, promoting quality submissions to the project's information system. To evaluate the coverage and quality of MyOSD data submissions, we compared the sea surface temperature measurements acquired through OSD, MyOSD, and automatic in situ systems and satellite measurements. Our results show that the quality of citizen-science measurements was comparable to that of scientific measurements. As 79% of MyOSD measurements were conducted in geographic areas not covered by automatic in situ or satellite measurement, citizen scientists contributed significantly to worldwide oceanographic data gathering. Furthermore, survey results indicate that participation in MyOSD made citizens feel more engaged in ocean issues and may have increased their environmental awareness and ocean literacy
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