Mechanical lifting energy consumption in work activities designed by means of the "revised NIOSH lifting equation"\u80\u9d

The aims of the present work were: to calculate lifting energy consumption (LEC) in work activities designed to have a growing lifting index (LI) by means of revised NIOSH lifting equation; to evaluate the relationship between LEC and forces at the L5-S1 joint. The kinematic and kinetic data of 20 workers were recorded during the execution of lifting tasks in three conditions. We computed kinetic, potential and mechanical energy and the corresponding LEC by considering three different centers of mass of: 1) the load (CoML); 2) the multi-segment upper body model and load together (CoMUpp+L); 3) the whole body and load together (CoMTot). We also estimated compression and shear forces. Results shows that LEC calculated for CoMUpp+L and CoMTot grew significantly with the LI and that all the lifting condition pairs are discriminated. The correlation analysis highlighted a relationship between LEC and forces that determine injuries at the L5-S1 joint

Numerical Modeling of Single-Lap Shear Bond Tests for Composite-Reinforced Mortar Systems

The large demand of reinforcement systems for the rehabilitation of existing concrete and masonry structures, has recently increased the development of innovative methods and advanced systems where the structural mass and weight are reduced, possibly avoiding steel reinforcements, while using non-invasive and reversible reinforcements made of pre-impregnated fiber nets and mortars in the absence of cement, commonly known as composite-reinforced mortars (CRMs). To date, for such composite materials, few experimental studies have been performed. Their characterization typically follows the guidelines published by the Supreme Council of Public Works. In such a context, the present work aims at studying numerically the fracturing behavior of CRM single-lap shear tests by implementing a cohesive zone model and concrete damage plasticity, in a finite element setting. These specimens are characterized by the presence of a mortar whose mechanical behavior has been defined by means of an analytical approximation based on exponential or polynomial functions. Different fracturing modes are studied numerically within the CRM specimen, involving the matrix and reinforcement phases, as well as the substrate-to-CRM interface. Based on a systematic investigation, the proposed numerical modeling is verified to be a useful tool to predict the response of the entire reinforcement system, in lieu of more costly experimental tests, whose results could be useful for design purposes and could serve as reference numerical solutions for further analytical/experimental investigations on the topic

Stabilization of Arthrospira platensis with high-pressure processing and thermal treatments: Effect on physico-chemical and microbiological quality

Arthrospira platensis (Spirulina) is a cyanobacterium that has been recently studied for food applications due to its high biological and nutritional value. When A. platensis is used as an ingredient in food applications, proper treatments have to be applied in order to reduce microbial contamination. This work compared the effect of thermal treatments (sterilization at 121℃ and pasteurization at 90℃) and high-pressure processing (400, 600 MPa) on the chemical, physico-chemical, and microbial quality of 5% (wt/vol) A. platensis aqueous suspensions. Total antioxidant capacity, total polyphenols content, color, and pigments content were not strongly lowered/modified by the high-pressure processing (HPP) treatments. HPP at 400 MPa even improved the release of C-phycocyanin from the biomass because of the breakage of cell walls. HPP treatments were comparable to pasteurization in reducing yeasts, coliforms, Staphylococci, and total bacterial count. Conversely, sterilization was the only treatment that guaranteed the inactivation of spore-forming species but affecting the final quality. Novelty impact statement: High-pressure processing (HPP) treatments were found to be a good strategy to preserve or even improve some physical and chemical properties of Arthrospira platensis (Spirulina), in particular antioxidant capacity, polyphenols, color, and pigments content. Furthermore, HPP treatments were comparable to pasteurization in reducing microbial cell count, while sterilization was the only treatment able to ensure the inhibition of spore-forming species

Solvent-free copper-catalyzed azide-alkyne cycloaddition under mechanochemical activation

The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized. This new, efficient, facile and eco-friendly procedure has been tested on a number of different substrates and in all cases afforded the corresponding 1,4-disubstituted 1,2,3-triazole derivatives in high yields and purities. The final compounds were isolated in almost quantitative overall yields after simple filtration, making this procedure facile and rapid. The optimized CuAAC protocol was efficiently applied even with bulky functionalized β-cyclodextrins (β-CD) and scaled-up to 10 g of isolated product

Pendugaan laju sedimentasi pada kolam tanah budidaya ikan patin intensif di Desa Koto Mesjid Kecamatan XIII Koto Kampar

The potential of fisheries in Koto Mesjid village XIII Koto Kampar districts has had a tremendous impact on people's income. The total area of ​​the Patin pond in Koto Mesjid village has reached 62 hectares. The production reaches six tons per day. Training in prediction the rate of sedimentation in intensive catfish aquaculture ponds in the village of Koto Mesjid has resulted in a way to monitor the quality of pond water through the measurement of suspended solids using a solid trap device. The average suspended solids at all pond ages are 19.5 ml / L per day and 129.25 ml / L per week. Based on this data, the management of the pond bottom must be carried out every harvest, mainly when drying the pond needs to drain mud. Patin fish farmers have very high enthusiasm to practice the tools in their respective ponds. The existence of this counseling is very useful in providing knowledge so that people who work as Patin fish farmers can manage the time to replace pond water easily.Potensi perikanan di Koto Mesjid Kecamatan XIII Koto Kampar telah memberikan dampak yang luar biasa bagi pendapatan masyarakat. Total luas kolam Patin di Koto Mesjid telah mencapai 62 hektar. Hasil produksi mencapai enam ton perhari. Pelatihan pendugaan laju sedimentasi pada kolam tanah budidaya ikan patin intensif di desa Koto Mesjid telah menghasilkan cara pemantauan kualitas air kolam melalui pengukuran padatan tersuspensi menggunakan alat perangkap padatan. Rata-rata padatan tersuspensi pada semua umur kolam adalah 19,5 ml/L perhari dan 129,25 ml/L per minggu. Berdasarkan data ini maka pengelolaan dasar kolam harus dilakukan setiap panen terutama saat pengeringan kolam perlu pengurasan lumpur. Petani ikan Patin memiliki antusias sangat tinggi untuk mempraktekkan alat pada kolam masing-masing. Adanya penyuluhan ini sangat bermanfaat dalam memberikan bekal ilmu pengetahuan sehingga masyarakat yang berprofesi sebagai petani ikan Patin dapat mengatur waktu penggantian air kolam dengan mudah

Dataset on gait patterns in degenerative neurological diseases

We collected the gait parameters and lower limb joint kinematics of patients with three different types of primary degenerative neurological diseases: (i) cerebellar ataxia (19 patients), (ii) hereditary spastic paraparesis (26 patients), and (iii) Parkinson's disease (32 patients). Sixty-five gender-age matched healthy subjects were enrolled as control group. An optoelectronic motion analysis system was used to measure time-distance parameters and lower limb joint kinematics during gait in both patients and healthy controls

Effect of Interlayer and Inclined Screw Arrangements on the Load-Bearing Capacity of Timber-Concrete Composite Connections

The solution of timber-to-concrete composite (TCC) floors represents a well-established construction technique, which is consistently used for both the retrofitting of existing timber floors and the realization of new diaphragms. The success of TCC floors relies on the intrinsic effectiveness in increasing both the in-plane (for lateral loads) and the out-of-plane (for gravity loads) performance of existing timber floors. As a widespread retrofit intervention, it is common to use existing floorboards as a permanent formwork for the concrete pouring. Rather few research studies of literature, in this regard, highlighted an overall reduction of load capacity and slip modulus due to the presence of such an interposed interlayer. In this regard, the present paper focuses on the use of screws as efficient mechanical connectors and analyses different configurations and inclination angles for their arrangement. This main goal is achieved by performing parametric Finite Element (FE) numerical analyses, validated on previous experimental tests, in order to specifically investigate the influence of the in-between interlayer, as well as the role of friction phenomena and the influence of the test setup and experimental protocol to achieve the basic mechanical performance indicators