Significant population genetic structuring in Rhyzopertha dominica across Turkey: Biogeographic and practical implications

Rhyzopertha dominica is a key pest of stored grain. Understanding the movement of this beetle on broad geographic scales is crucial, particularly when developing strategies to prevent the spread of phosphine resistance. We assessed population genetic structuring in this pest across Turkey, using a combination of mitochondrial (cytochrome oxidase I) and microsatellite markers. In addition, we screened samples for Wolbachia, as this endosymbiont has previously been suggested to be associated with low mitochondrial genetic diversity in this beetle. Mitochondrial genetic diversity was low, with only six haplotypes identified. The genetic diversity was, however, substantially higher than that previously found in Australia or India, suggesting that R. dominica may have originated in the Middle East. Wolbachia were detected only at a single site, indicating they are not impacting the mitochondrial genetic diversity of R. dominica across Turkey. Microsatellite markers indicated there is significant geographic genetic structuring across Turkey, even among sites less than 100 km apart, suggesting there is little movement of beetles across regions within the country. This contrasts with the significantly higher levels of gene-flow found in Australia and the United States. We suggest that the limited movement of beetles across Turkey may be due to a combination of the historically localised agricultural practices (which limits anthropogenic movement among regions), and the mountainous landscape (which limits active flight among regions). Our results demonstrate that the movement of stored product pests may differ significantly across studies conducted in different countries. As a consequence, phosphine resistance management strategies must incorporate region specific information on the extent of beetle movement.     

Numerical evaluation of new Austrian tunneling method excavation sequences: A case study

The main aspects that require attention in tunnel design in terms of safety and economy are the precise estimation of probable ground conditions and ground behavior during construction. The variation in rock mass behavior due to tunnel excavation sequence plays an important role during the construction stage.The purpose of this research is to numerically evaluate the effect of excavation sequence on the ground behavior for the Lowari tunnel project, Pakistan. For the tunnel stability, the ground behavior observed during the actual partial face excavation sequence is compared with the top heading and bench excavation sequence. For this purpose, the intact rock parameters are used along with the characterization of rock mass joints related parameters to provide input for numerical modelling via FLAC 2D. The in-situ stresses for the numerical modelling are obtained using empirical equations. From the comparison of the two excavation sequences, it was observed that the actual excavation sequence used for Lowari tunnel construction utilized more support than the top heading and bench method. However, the actual excavation sequence provided good results in terms of stability.     

Microwave drying of a low-rank sub-bituminous coal

The moisture contents of coals are often too high and need to be reduced before further processing. In this study, the application of microwave radiation as an alternative energy source for the drying of a sub-bituminous coal was investigated. Firstly, the permittivities of the coal were evaluated as a function of temperature and frequency. Secondly, the drying kinetics were studied in a 2.45 GHz microwave system and the effects of incident microwave power, sample mass and initial moisture contents were determined. The results demonstrated that microwave drying had several advantages over conventional drying such as increased drying rates and lower final moisture contents. In some tests, magnetite was added as a susceptor to increase the drying rates. Thirdly, the drying data were fitted to ten exponential decay models, and although reasonable agreement was observed with all the models, the best fit was obtained with the Midilli–Kucuk model. Finally, the effective diffusion coefficients of moisture and also the activation energy of the diffusion process were estimated and used to further elucidate the mechanism of microwave drying.     

Wave climate analysis for the design of wave energy harvesters in the Mediterranean Sea

The objective of this paper is to provide a synthetic tool for determining expeditiously the wave climate conditions in several areas of the Mediterranean Sea. In the open literature, several authors have already conducted this specific analysis also for the area under examination in this paper. However, the need of discussing aspects strictly related to the design of wave energy harvesters is still relevant. Therefore, considering the variety of devices and the amount of information needed for conducting both an energy-wise optimization and a structural reliability assessment, a holistic view on the topic is provided. Specifically, the paper elucidates the theoretical aspects involved in the estimation of wave energy statistics and in the calculation of relevant return values. Next, it provides synthetic data representing the mean wave power and the return value of extreme events in several coastal areas of the Mediterranean Sea. In this regard, the paper complements information available in the open literature by discussing the influence of the directional pattern of the sea states in the determination of sea state statistics as well as in the design of a wave energy harvester.     

Application of the guideline for overbreak control in granitic rock masses in Korean tunnels

Overbreak, one of the most important factors in the evaluation of the results of a tunnel blasting, has been a challenging target for many tunnelling engineers as it is directly connected with construction cost. In Korea where the space produced by overbreak should be filled with shotcrete or the lining concrete, various efforts have been made to reduce overbreak. In connection with this, a guideline for overbreak control has been suggested by the author in a previous study based upon full scale field tests. The guideline provides the instructions as to how to draw a contour line, to drill blasting holes, and to charge explosives to reduce overbreak.In this study, field investigations and tests are carried out to check the feasibility of the suggested guideline for four tunnels in Korea. The average overbreak for the cases performed according to the guideline is compared with that for usual cases. The results from the comparison show that the guideline is generally working well and the overbreak is decreased by 10–77%, and it is analyzed that the overbreak reduction corresponds to approximately 65,000 US$ to 130,000 US$ in a support cost reduction.It is concluded that not only the use of a computerized drilling jumbo but also the carefully performed operations are important for the overbreak control.     

Air pollution assessment in urban areas and its impact on human health in the city of Quetta, Pakistan

Nowadays, air over major cities throughout the world has become overburdened with gases produced by automobiles. The death rate due to automobile pollution is increasing rapidly in the metropolitan areas. With passage of time, people realized that polluted air has serious effects on their health, climate and economics. Weather and climate have integrated impact on human activities resulting in worldwide concentration of the particulates of environmental pollution, viz., chlorofluorocarbons, carbon dioxide, methane, nitrogen oxide, lead and several other dust and gaseous particles. Like many other mega cities in the world the ambient air quality of Quetta, Pakistan is also deteriorating nowadays. Automobile exhausts and certain industrial pollutants produce O₃ by photochemical reactions. The particulate matter, particularly less than 10 μm in size, can pass through the natural protective mechanism of human respiratory system and plays an important role in genesis and augmentation of allergic disorders. Sources of air pollution in the area and the unique problem arising out of the emission from the vehicles, industries, etc. have been described. Ambient air quality was monitored along with micrometeorological data and the results are discussed. The status of air pollution in the area has been evaluated and a questionnaire survey was conducted to estimate the allergic symptoms and exposure to assess the respiratory disorders. The data are analyzed to evaluate the critical situation arising out of the emission of air pollutants and the impact on human health due to respirable diseases (RDs) in middle class sub-population (activity-wise) in the area assessed. A strategic air quality management plan has been proposed. For the mitigation of air pollution problems in the city, different measures to be adopted to maintain the balance between sustainable development and environmental management have been discussed. Air pollution has significant effects on exacerbation of asthma, allergy and other respiratory diseases.     

One-step synthesis of the 3D flower-like heterostructure MoS2/CuS nanohybrid for electrocatalytic hydrogen evolution

In this work, a facile one-step hydrothermal method was developed to fabricate three types different of nanomaterials: the two-dimension (2D) of MoS₂ nanosheets; 3D spherical CuS nanoparticles; and 3D flower-like heterostructure of MoS₂/CuS nanohybrid, respectively. The as-synthesized MoS₂, CuS and MoS₂/CuS were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD) etc. The morphology of the MoS₂/CuS nanohybrid is different from the MoS₂ nanosheets and CuS nanoparticles. The hydrogen evolution reaction (HER) activity of MoS₂ nanosheets, CuS nanoparticles and MoS₂/CuS nanohybrid, were investigated by the Linear Sweep Voltammetry (LSV) and Tafel slope. The HER activity of MoS₂/CuS nanohybrid is better than those of MoS₂ nanosheets and CuS nanoparticles, which can be attributed to the good electron-transport ability of CuS and the strong reduction ability of hydrogen ions by MoS₂. Thus, MoS₂/CuS nanohybrid exhibited excellent activity for HER with a small onset potential of 0.15 V, a low Tafel slope of 63 mV dec^?1, and relatively good stability. However, the MoS₂ nanosheets and CuS nanoparticles respectively shows a bigger onset potential of 0.25 V and 0.35 V, a higher Tafel slope of 165 and 185 mV dec^?1. This 3D flower-like heterostructure of MoS₂/CuS nanohybrid catalyst exhibits great potential for renewable energy applications.     

Cumulative frequency distribution of solar insolation at Quetta, Pakistan

An inverse Gaussian relationship between percentage cumulative frequency and energy (in MJ/m²/day) is obtained from solar insolation data of Quetta, Pakistan.     

A Novel Hybrid Method for River Discharge Prediction

Accurate prediction of river discharge is essential for the planning and management of water resources. This study proposes a novel hybrid method named HD-SKA by integrating two decomposition techniques (termed as HD) with support vector regression (SVR), K-nearest neighbor (KNN) and ARIMA models (combined as SKA) respectively. Firstly, the proposed method utilizes local mean decomposition (LMD) to decompose the original river discharge series into sub-series. Next, ensemble empirical mode decomposition (EEMD) is employed to further decompose the LMD-based sub-series into intrinsic mode functions. Further, the EEMD decomposed components are used as inputs in three data-driven models to predict river discharge respectively. The prediction of all components is then aggregated to obtain the results of HD-SVR, HD-KNN and HD-ARIMA models. The final prediction is obtained by taking the average prediction of these models. The proposed method is illustrated using five rivers in Indus Basin System. In five case studies, six models were built to compare the performance of the proposed HD-SKA model. The data analysis results show that the HD-SKA model performs better than all other considered models. The Diebold-Mariano test confirms the superiority of the proposed HD-SKA model over ARIMA, SVR, KNN, EEMD-ARIMA, EEMD-KNN, and EEMD-SVR models.