Issues on Design of Piled Raft Foundation

A piled raft foundation consists of a thick concrete slab reinforced with steel which covers the entire contact area of the structure, in which the raft is supported by a group of piles or a number of individual piles. Bending moment on raft, differential and average settlement, pile and raft geometries are the influencing parameters of the piled raft foundation system. In this paper, a detailed review has been carried out on the issues on the raft foundation design. Also, the existing design procedure was explained

Enhancing Synchrony in Chaotic Oscillators by Dynamic Relaying

In a chain of mutually coupled oscillators, the coupling threshold for synchronization between the outermost identical oscillators decreases when a type of impurity (in terms of parameter mismatch) is introduced in the inner oscillator(s). The outer oscillators interact indirectly via dynamic relaying, mediated by the inner oscillator(s). We confirm this enhancing of critical coupling in the chaotic regimes of R\"ossler system in absence of coupling delay and in Mackey-Glass system with delay coupling. The enhancing effect is experimentally verified in electronic circuit of R\"ossler oscillators.Comment: 4 pages, 9 figure

Role of serum LDH in preeclampsia as a prognostic factor – a cross sectional case control study in tertiary care hospital

Background: LDH is an intracellular cytoplasmic enzyme. It is ubiquitous to all the major organ systems. Cellular enzymes in extracellular space have no metabolic function, although they serve as indicators of disturbances in cellular integrity. Serum LDH is abnormal in many disorders, therefore total serum LDH is highly sensitive but nonspecific test. In preeclampsia also LDH may be elevated and can indicate the prognosis for both mother and fetus. We conducted this study to examine the relationship between lactate dehydrogenase concentration and the severity of the disease and the occurrence of its complications.Methods: 200 pre-eclamptic women (121 with mild and 79 with severe pre-eclampsia) and 200 healthy normotensive controls were studied prospectively at Government Kilpauk medical college and hospital between January and December 2015. Demographic, hemodynamic, and laboratory data were compared among the three groups. The symptoms and complications of severe pre-eclampsia along with fetal outcome were analyzed according to the levels of LDH.Results: Severely pre-eclamptic patients were significantly younger, with low gravidity and parity. On the other hand, they had significantly increased systolic and diastolic pressure and liver enzymes, uric acid, urine albumin, and LDH levels. The symptoms and complications of pre-eclampsia along with perinatal mortality were increased significantly in patients with LDH >800 IU/l compared with those who had lower levels.Conclusions:  Lactate dehydrogenase is a useful biochemical marker that reflects the severity of pre-eclampsia. In our study, LDH has been evaluated as a biochemical marker for preeclampsia and as a prognosticator of the disease severity. Detection of high-risk patients with increased levels of LDH mandate close monitoring and management to prevent maternal and fetal morbidity and mortality

Transistor-Clamped Multilevel H-Bridge Inverter in Si and SiC Hybrid Configuration for High-Efficiency Photovoltaic Applications

Using wide bandgap (WBG) devices has been a promising solution to improve the efficiency of power inverters for photovoltaic (PV) applications. However, for multilevel inverters, using WBG devices to improve the inverter efficiency can increase the system cost dramatically due to the high price of WBG devices in the present market as well as the large number of power devices typically required in multilevel inverter topologies. In this paper, a five-level transistor clamped H-bridge (TCHB) inverter will be further investigated. This inverter requires much lower number of semiconductor switches and fewer isolated dc sources than the conventional cascaded H-bridge inverter. To improve the inverter efficiency, semiconductor switches operating at carrier frequency will be configured by Silicon Carbide (SiC) devices to reduce the dominant switching losses, while the switches operating at fundamental output frequency (i.e., grid frequency) will be constituted by Silicon (Si) devices. As a result, both of the peak efficiency and California Energy Commission (CEC) efficiency of the TCHB inverter are significantly improved and dramatic system cost increase is avoided. In addition, due to the faster saturation characteristic of the IGBT devices, the large short-circuit current in SiC MOSFETs is constrained under the condition of load short-circuit faults. In other words, this proposed “SiC+Si” hybrid TCHB inverter can ride through a load short-circuit fault. Simulation and experimental results are presented to confirm the benefits of this proposed hybrid TCHB inverter

Global mangrove deforestation and its interacting social-ecological drivers: a systematic review and synthesis

Bhowmik, A. K., Padmanaban, R., Cabral, P., & Romeiras, M. M. (2022). Global mangrove deforestation and its interacting social-ecological drivers: a systematic review and synthesis. Sustainability (Switzerland), 14(8), 1-24. [4433]. https://doi.org/10.20944/preprints202203.0052.v1, https://doi.org/10.3390/su14084433 ---------------------------------- Funding Information: Funding: This study was supported through the FCT (Fundação para a Ciência e a Tecnologia) under the projects PTDC/CTA-AMB/28438/2017—ASEBIO, UIDB/04152/2020—Centro de Investi- Investigação em Gestão de Informação (MagIC), UIDB/04152/2020 Centro de Investigação em Gestão de Informação (MagIC) and UID/AGR/04129/2020 (LEAF/ISA).Globally mangrove forests are substantially declining and a globally synthesized database of the drivers of deforestation and drivers’ interaction is scarce. Here we synthesized the key social-ecological drivers of global mangrove deforestation by reviewing about two hundred published scientific studies over the last four decades (from 1980 to 2021). Our focus was on both natural and anthropogenic drivers with gradual and abrupt impacts and their geographic ranges of effects and how these drivers interact. We also summarized the patterns of global mangrove coverage decline between 1990 and 2020 and identified the threatened mangrove species and their geographic ranges. Our consolidated studies reported a 8,600 km2 decline in the global mangrove coverage between 1990 and 2020 with the highest decline occurring in South and Southeast Asia (3870 km2). We could identify 11 threatened mangrove species, two of which are critically endangered (Sonneratia griffithii and Bruguiera hainseii). Our reviewed studies pointed to aquaculture and agriculture as the predominant driver of global mangrove deforestation though the spatial distribution of their impacts varied. Gradual climate variations, i.e. seal-level rise, long-term precipitation and temperature changes and driven coastline erosion, constitute the second major group of drivers. Our findings underline a strong interaction across natural and anthropogenic drivers with the strongest interaction between the driver groups aquaculture and agriculture and industrialization and pollution. Our results suggest prioritizing globally coordinated empirical studies linking drivers and mangrove changes and a global development of policies for mangrove conservation.preprintpublishe

Global mangrove deforestation and its interacting social-ecological drivers: a systematic review and synthesis

Globally, mangrove forests are substantially declining, and a globally synthesized database containing the drivers of deforestation and drivers’ interactions is scarce. Here, we synthesized the key social-ecological drivers of global mangrove deforestation by reviewing about two hundred published scientific studies over the last four decades (from 1980 to 2021). Our focus was on both natural and anthropogenic drivers with their gradual and abrupt impacts and on their geographic coverage of effects, and how these drivers interact. We also summarized the patterns of global mangrove coverage decline between 1990 and 2020 and identified the threatened mangrove species. Our consolidated studies reported an 8600 km2 decline in the global mangrove coverage between 1990 and 2020, with the highest decline occurring in South and Southeast Asia (3870 km2). We could identify 11 threatened mangrove species, two of which are critically endangered (Sonneratia griffithii and Bruguiera hainseii). Our reviewed studies pointed to aquaculture and agriculture as the predominant driver of global mangrove deforestation though their impacts varied across global regions. Gradual climate variations, i.e., sea-level rise, long-term precipitation, and temperature changes and driven coastline erosion, salinity intrusion and acidity at coasts, constitute the second major group of drivers. Our findings underline a strong interaction across natural and anthropogenic drivers, with the strongest interaction between the driver groups aquaculture and agriculture and industrialization and pollution. Our results suggest prioritizing globally coordinated empirical studies linking drivers and mangrove deforestation and global development of policies for mangrove conservation.info:eu-repo/semantics/publishedVersio

Selective harmonic elimination in awide modulation range using modified Newton-raphson and pattern generation methods for a multilevel inverter

Considering the aim of having low switching losses, especially in medium-voltage and high-power converters, the pre-programmed pulse width modulation technique is very useful because the generated harmonic content can be known in advance and optimized. Among the different low switching frequency techniques, the Selective Harmonics Elimination (SHE) modulation method is most suitable because of its direct control over the harmonic spectrum. This paper proposes a method for obtaining multiple solutions for selectively eliminating specific harmonics in a wide range of modulation indices by using modified Newton-Raphson (NR) and pattern generation techniques. The different pattern generation and synthesis approach provide more degrees of freedom and a way to operate the converter in a wide range of modulation. The modified Newton-Raphson technique is not complex and ensures fast convergence on a solution. Moreover, multiple solutions are obtained by keeping a very small increase in the modulation index. In the previous methods, solutions were not obtainable at all modulation indices. In this paper, only exact solutions to the low-order harmonics elimination for Cascaded H-bridge inverter are reported for all modulation indices. Analytical and simulation results prove the robustness and correctness of the technique proposed in this paper. 2018 by the authors.Acknowledgments: This (publication, report, etc.) was made possible by NPRP grant # [X-033-2-007] from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

Electrophysiological responses of banana pseudostem weevil, Odoiporus longicollis Olivier (Coleoptera: Curculionidae) to methyl jasmonate, 1-hexanol and host plant extract

53-57The banana pseudostem weevil (BSW), Odoiporus longicollis Olivier (Coleoptera: Curculionidae) is one of the most destructive pests of banana and plantains. Our laboratory bioassay studies showed that out of 50 host plants related volatile chemicals screened against BSW, only methyl jasmonate (MeJA) and 1-hexanol was electrophysiologically and behaviourally active. Here, we investigated the influence of host plant extract (HPE) on two semiochemicals, namely methyl jasmonate (MeJA) and 1-hexanol, both independently and in combination, in the electroantennogram (EAG) response in BSW. The results showed that HPE alone elicited greater EAG response only in males suggesting that males involved predominantly in the host plant selection. Addition of HPE to MeJA increased significantly higher EAG response in females and the response was insignificant in males. Similarly, the addition of HPE to 1-hexanol evoked higher response in females but decreased antennal activity was recorded in males compared to HPE alone. The HPE showed additive effect on MeJA and 1-hexanol in their EAG responses only in female BSW. The result also revealed that 1-hexanol+HPE blend exhibited enhanced EAG response compared to 1-hexanol alone in both sexes