Spillover effects of trade and foreign direct investment on economic growth: an implication for sustainable development

Environment, Development and Sustainability - This paper explores the advantages of international trade and foreign direct investment (FDI), which can be the main factors of transferring technology...     

A Solvent-Free Approach for Production of Films from Pectin and Fungal Biomass

Self-binding ability of the pectin molecules was used to produce pectin films using the compression molding technique, as an alternative method to the high energy-demanding and solvent-using casting technique. Moreover, incorporation of fungal biomass and its effects on the properties of the films was studied. Pectin powder plasticized with 30% glycerol was subjected to heat compression molding (120 °C, 1.33 MPa, 10 min) yielding pectin films with tensile strength and elongation at break of 15.7 MPa and 5.5%, respectively. The filamentous fungus Rhizopus oryzae was cultivated using the water-soluble nutrients obtained from citrus waste and yielded a biomass containing 31% proteins and 20% lipids. Comparatively, the same strain was cultivated in a semi-synthetic medium resulting in a biomass with higher protein (60%) and lower lipid content (10%). SEM images showed addition of biomass yielded films with less debris compared to the pectin films. Incorporation of the low protein content biomass up to 15% did not significantly reduce the mechanical strength of the pectin films. In contrast, addition of protein-rich biomass (up to 20%) enhanced the tensile strength of the films (16.1–19.3 MPa). Lastly, the fungal biomass reduced the water vapor permeability of the pectin films.     

Discovering and characterizing farm households’ resilience under water scarcity

Water scarcity at an alarming rate has been a limiting factor for sustainable agriculture in arid and semi-arid environments of the world. It has resulted in a number of problems such as poverty and food insecurity among farm households. Therefore, building and improving resilience, as a way to mitigate the impacts of water scarcity, is important for farm households. But one of the significant steps for planning to improve farm households’ resilience under water scarcity is investigation of the current level of resilience of these households and understanding their variances. Therefore, this study offers a classification of farm households’ diversity based on resilience. Primary data were collected from 260 randomly selected farm households in 21 villages around Parishan wetland, Iran. Farm Household Resilience Scale was used to measure resilience. Cluster analysis suggested three groups: highly, medium-, and low-resilient farm households. The results of comparing three groups revealed that highly resilient farm households characterize with higher risk management, more agricultural water security, more positive psychological traits, and better knowledge management. Also, they had better water quality, attended more agricultural extension activities, and used modern irrigation systems. Farm households’ resilience map using GIS software illustrated that there is a relationship between resilience and farm location from the wetland. The findings of this study could be used by planner and policy-makers to improve farm households’ resilience in arid and semi-arid environments. Improvement in knowledge management system is recommended as one of the most effective policy instruments in building resilience.     

Analytical solutions of nonlinear and variable-parameter transport equations for verification of numerical solvers

All numerical codes developed to solve the advection–diffusion-reaction (ADR) equation need to be verified before they are moved to the operational phase. In this paper, we initially provide four new one-dimensional analytical solutions designed to help code verification; these solutions are able to handle the challenges of the scalar transport equation including nonlinearity and spatiotemporal variability of the velocity and dispersion coefficient, and of the source term. Then, we present a solution of Burgers’ equation in a novel setup. Proposed solutions satisfy the continuity of mass for the ambient flow, which is a crucial factor for coupled hydrodynamics-transport solvers. By the end of the paper, we solve hypothetical test problems for each of the solutions numerically, and we use the derived analytical solutions for code verification. Finally, we provide assessments of results accuracy based on well-known model skill metrics.     

Ergonomic design and evaluation of a diagnostic ultrasound transducer holder

Background. Work-related musculoskeletal disorders (WMSDs) are injuries and disorders that affect the body’s movement and musculoskeletal system. Awkward postures represent one of the major ergonomic risk factors that cause WMSDs among sonographers while working with an ultrasound transducer. This study aimed to design and evaluate a new holder for the ultrasound transducer. Materials and methods. In the first phase a new holder was designed for the transducer, considering design principles. Evaluation of the new holder was then carried out by electrogoniometry and a locally perceived discomfort (LPD) scale. Results. The application of design principles to the new holder resulted in an improvement of wrist posture and comfort. Wrist angles in extension, flexion, radial deviation and ulnar deviation were lower with utilization of the new holder. The severity of discomfort based on the LPD method in the two modes of work with and without the new holder was reported with values of 1.3 and 1.8, respectively (p?<?0.05). Conclusion. Overall, this study indicated that applying ergonomics design principles was effective in minimizing wrist deviation and increasing comfort while working with the new holder.     

Optimal Design of Ozone Bleaching Parameters to Approach Cellulose Nanofibers Extraction from Sugarcane Bagasse Fibers

Cellulose nanofibers (CNFs) were isolated from sugarcane bagasse (SCB) through the combination of bio-refinery, sulfur-free, and totally chlorine free (TCF) chemo-mechanical pretreatments, with a focus on the optimal design of ozone bleaching parameters based on a response surface methodology (RSM). For this purpose, the most effective parameters in ozone bleaching (temperature, time, and pulp consistency) were set between 40 and 85 °C, 60 and 360 min, and 1–5 wt%, respectively. High-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), Kappa number, and scanning electron microscopy (SEM) were used to chemically and morphologically characterize the SCB fibers. The size distribution and morphology of CNFs were also evaluated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). HPLC analysis revealed that percentage of cellulose increased from 41.5 to 91.39% after chemical pretreatments. FTIR and Kappa number analyses also confirmed the successful isolation of cellulose fibers from the SCB fibers after chemical pretreatments. Furthermore, DLS results showed that the hydrodynamic diameter of the isolated cellulose fibers reduced to 268 nm by dint of ultrasonication. Additionally, TEM images confirmed the isolation of CNFs: the average diameter of cellulose fibers decreased to about 28 nm after mechanical steps and the yield of fibrillation was found to be around 99%. According to the obtained results, the applied chemo-mechanical treatment appears to be promising for green and facile isolation of CNFs.     

Assessment of a heat pipe solar collector with nanofluids

Environmental Science and Pollution Research - This research was designed to experimentally study the influence of using three metal oxide nanofluids at different high flow rates with various mass...     

A novel pollution index based on the bioavailability of elements: a study on Anzali wetland bed sediments

In this research, we study on the distribution of several elements in bed sediments of Anzali wetland. Anzali, one of the most important international wetlands, is located on the southern coast of the Caspian Sea in Iran. This wetland receives discharges of domestic, agricultural, and industrial wastewater, which affect the distribution of elements. Our contribution in this study is threefold. First, we measured the total concentration of metals as well as their chemical partitioning and bioavailability in the sediments. Second, we calculated anthropogenic portions of metals in the sediment of this area. The results reveal anthropogenic portion of metals as Mo > Mn > Cd > As > Zn > Hg > Co > Sn > Cu > V > Ag > Ni > Pb > Fe > Cr > Al, respectively. We evaluated the intensity of pollution by using an enrichment factor, the geo-accumulation index and the pollution index. All these indices do not take into consideration the bioavailability of the elements. As our third and most important contribution, we introduced a new formula that takes into account the bioavailability of different elements. In comparison with aforementioned pollution indices, our newly introduced pollution index has a higher Pearson correlation with anthropogenic portion of metals. This high-correlation coefficient shows that our proposed pollution index is an effective indicator for determining the level of pollution, while other indices preserve their own merits.