Full Turnover Research Articles

Organocatalytic asymmetric synthesis of Si-stereogenic silacycles

A strong and confined Brønsted acid catalyzed enantioselective cyclization of bis(methallyl)silanes provides enantioenriched Si-stereogenic silacycles. High enantioselectivities of up to 96.5:3.5 er were obtained for a range of bis(methallyl)silanes. NMR and ESI-MS studies reveal that the formation of a covalent adduct irreversibly inhibits turnover. Remarkably, we found that acetic acid as an additive promotes the collapse of this adduct, enabling full turnover. Experimental investigation and density functional theory (DFT) calculations were conducted to elucidate the origin of this phenomenon and the observed enantioselectivity.

Understanding stratification and turnover dynamics of a tropical lake using extensive field observations and 3D hydrodynamic simulations

The stratification and turnover dynamics of a tropical lake were evaluated using field observations and 3D hydrodynamic simulations. Located in the Philippines, Sampaloc Lake is a 104-ha and 27-m deep volcanic crater lake with enclosed watershed, which is at risk of the impacts of intensive aquaculture, rapid urbanization and climate change. Temperature, dissolved oxygen (DO) and chlorophyll-a (Chl-a) were measured at seven sampling stations using a multiprobe. Kruskal-Wallis test revealed that the three parameters are not significantly different among stations, indicating that one sampling station can represent the water quality of the whole lake. Schmidt's Stability Index (SSI) and thermocline strength, together with DO and Chl-a gradients decreased from October 2022 (stratified) to January 2023 (turnover). After successfully verifying the 3D numerical model, sensitivity analyses of water temperature to varying weather, together with particle tracking simulations, were implemented to determine the timing of isothermal state, upwelling, partial mixing, and full turnover. Compared to air temperature, variations in wind speed have more pronounced effects on the delay or progression of isothermal conditions in the lake based on SSI, Lake Number and Wedderburn Number. Isothermal conditions do not necessarily coincide with the timing of full turnover, with the latter being delayed by two days than the former, on average. Results revealed that full turnover can occur several weeks earlier with the decrease in AT and increase in WS. This study can advance the understanding of thermal and turnover dynamics of stratified tropical lakes, leading to better management of the water quality of these water bodies.

Ruthenium Complexes with a Tridentate Anionic Bisfluoroalkoxy‐Carbene Ligand – Valuable Latent Olefin Metathesis Catalysts for Polymerisation Reactions

AbstractA Grubbs‐type ruthenium complex bearing a tridentate anionic bisfluoroalkoxy‐carbene was synthesised and fully characterised. Under standard conditions, it proved to be inactive in olefin metathesis reactions, but the addition of HCl triggers its activity and allows the synthesis of a series of cyclic olefins and ethers as well as a stereoregular polynorbornene with an unexpectedly high content of trans‐configured double bonds, as found in commercially available polynorbornene (Norsorex®). Detailed structural studies and DFT calculations showed that the complex enters the catalytic cycle, but instead of performing a full turnover, it is caught as a stable intermediate that does not undergo further reactions. The addition of HCl causes dissociation of the fluoroalkoxy units, resulting in a compound that behaves similarly to standard Grubbs‐type complexes. To further understand this phenomenon, the corresponding Hoveyda‐Grubbs complex was also obtained and studied in detail; due to the absence of the phosphine ligand, its behaviour was different from that of its Grubbs‐type counterpart.

The Effect of Organizational Justice and Workload on Turnover Intention with Job Stress as a Mediating Variable

This study was conducted to examine the relationship of organizational justice to turnover intention and the relationship of workload to turnover intention using 221 employees of PT. Telkom Access Indonesia, Tbk Malang City as the subject of research. Researchers examined the direct effect of organizational justice and workload on turnover intention. Researchers use job stress as a mediator of organizational justice and workload relationships to turnover intention. This study used the Warp PLS 8.0 application to test the relationship between variables. The results of this study found that organizational justice had a significant effect on turnover intention, while workload in the study did not have a significant effect on turnover intention. Furthermore, job stress mediates the relationship of organizational justice to partial turnover intention and mediates the relationship of workload to full turnover intention.

Peculiarities of Dactylorhiza incarnata (Orchidaceae) cenopopulations under anthropogenic load

Studies of the biological characteristics of rare and vulnerable species of the Orchidaceae Juss family, to which Dactylorhiza incarnata (L.) Soo belongs, continue to be significant and relevant. The study of the structure of populations of such species in the territories of various nature management contributes to the assessment of their condition, the identification of the specifics of life, the development of measures for protection and restoration. The purpose of this work is to characterize some organismal parameters and the ontogenetic structure of D. incarnata roenopopulations (CP) in two habitats of the city of Kirov subjected to anthropogenic impact. The surveyed CPs are located in forb-grass communities overgrown with woody plants, the herbage of which is dominated by Poaceae species. When assessing the biotope conditions, the deviation of most soil factors from optimal ones was revealed. Immature, virginal and generative individuals are distinguished in the ontogenetic spectrum. The analysis of most parameters showed that the individuals CP of the Kirov sity have close morphomet-ric values with those given in the literature for other parts of the range and natural habitats. Generative individuals are higher here, the length of inflorescences and the number of flowers are greater, while the length of the lower leaf is shorter with equal or lesser width. CPs are few in number, the structure is normal incomplete: in CP 1 with a peak on generative individuals, in CP 2 - on immature and virginal ones; seed regeneration is suppressed. According to the “delta-omega” classification, CP 1 -is maturing, CP 2 - is young. In order to resume a steady full turnover of generations, increase the number and preserve the CP, it is necessary not only to regulate the anthropogenic load, but also to maintain moderate land use after fruit ripening.

Hypolimnetic oxygen depletion in a deep oligomictic lake under climate change

Dissolved oxygen (DO) concentration is a fundamental metric to describe climate-related alterations in deep lakes. Increasing water temperatures enhance thermal stratification, leading in temperate basins to a growing isolation of deep waters. This leads to the depletion of hypolimnetic DO, which adds up to limited nutrient circulation and restricted replenishment of the trophogenic layers. With vanishing convective mixing, it is commonly believed that the only source of hypolimnetic DO replenishment will be represented by deep intrusions of cold oxygenated waters from the tributaries. In this study, we first analyse the 1993–2020 long-term observed trends of DO concentrations in the subalpine deep oligomictic Lake Maggiore (Italy/Switzerland). Then, through an algorithm calculating daily intrusion depths and mass discharges of DO for the major tributaries, we show that deep insertions are suppressed for increasing winter water temperatures and residual thermal stratification. Turbulent entrainment is proved fundamental for DO replenishment, leading to mass discharges of DO released into the deep hypolimnion up to more than two orders of magnitude larger than the original ones from the tributaries. Last, we discuss the results of simulations made through a one-dimensional coupled ecological–hydrodynamic model about the possible effects of a full turnover on DO concentrations in the deep hypolimnion. Two cases are displayed, with the turnover taking place either now or with an anoxic hypolimnion deriving from decades of isolation due to severe climate warming. Through this study, climate warming is shown to be a fundamental driver of DO in Lake Maggiore, its depletion harming both water quality and the ecosystem.

Development of a frontal plow for smooth, furless plowing with cutoffs

The existing plows of smooth furless plowing do not provide a full turnover of layers within their own furrow and the incorporation of weeds, they have a high energy consumption. The aim of the study is to substantiate the parameters of the frontal plow cut-off, which ensures a high-quality performance of the technological process according to agrotechnical requirements with the lowest energy consumption during smooth furless plowing. An improved technology of smooth furrowless plowing has been developed, in which at first the seam is given a polygonal shape, then turned 180° within its own furrow. A frontal plow with offsets has been developed to implement the proposed technology. In the research, the laws and rules of theoretical mechanics, mathematical statistics, mathematical planning of experiments and methods of strain gauge were applied. It has been established by theoretical and experimental studies that when the frontal plow is cut off in the form of a triangular wedge, its height is 22 cm, the wing opening angle is 32°, the side edge angle is 36°, the required quality of smooth plowing is provided with the lowest energy consumption. With longitudinal distances between the plowshares of the body and the cut-off of at least 27 cm and between the disc coulter and the cut-off of 16 cm, the required quality of soil cultivation of the front plow is ensured in accordance with the established agro technical requirements.

Evaluation of business activity of a construction firm

The assessment of current production activities is carried out on the example of specialized construction and installation management with the help of turnover indicators as well as the level of efficiency of use of own and borrowed funds by the enterprise was determined.
 Indicators of this group characterize the results and efficiency of the current main activity of the enterprise, such analysis can be carried out both at the qualitative level and with the help of quantitative criteria.
 The main ones are production indicators, return on assets and turnover indicators. These indicators are of great importance for assessing the financial condition of the enterprise, because the speed of turnover, i.e. the speed of their conversion into cash, directly affects the solvency. The results of the calculation of the rate of return indicate that this fact (decrease in the turnover of fixed assets) may be associated with aging and wear of production equipment, i.e. we can say that the technical level of fixed assets of the object is low.
 The coefficient of sustainability of economic growth shows the average rate at which the company can develop further, without changing the already established relationship between different sources of funding. Summarizing the comparative data, we can say that if the management of the enterprise intends to increase its production capacity in order to increase production, it is necessary to change the financial policy. The results of calculations allow to show that at the analyzed enterprise there was a significant increase in the full production cycle and turnover as a whole. The duration of the operating cycle increased by more than 1.2 times and the duration of the financial cycle by almost 2 times. This was negatively affected by the factor of a significant slowdown in the turnover of inventories. Increasing the full production cycle in the future may cause negative trends in the enterprise as a whole, because this factor will primarily affect the amount of profit, which will affect the efficiency of production. The company activities to reduce the amount of net profit was influenced primarily by the acquisition of inventories, low-value perishable items and fixed assets, as well as repayment of accounts payable and payment of penalties.
 The period of turnover of the most liquid assets during the year varied from 0.04 to 17.5 days. The average chronological value in the period of saving money in the accounts of the enterprise was 7.5 days. This fact indicates that the company, despite the apparent well-being, is experiencing a serious shortage of funds. They were enough for a little over a week. Thus, with the help of analysis of economic indicators, you can describe the general condition of the company and the possibilities of its operation and development

Design, Analysis, Simulation, and Fabrication of a Novel Linear MEMS Capacitive Inclinometer

Design, analysis, simulation, and fabrication of a novel MEMS capacitive inclination sensor is reported. Through precise analysis, a linear relationship between output capacitance and the inclination angle of the structure is extracted which is attributed to the parallel plate structure of the capacitance sensor and tilt-dependent movement of the dielectric liquid at various angles. Our proposed inclinometer has three structures with 1, 2, and 4 parallel plate micro capacitors in each configuration. Capacitors in different structures have a common plate while other plates are separate, so different capacitors are realized. The sensor cavity is cylindrical and is half filled with silicone oil. Tilt application to the sensor leads to oil movement in the cavity and variation of different capacitors in the structure. For an analytical expression, we introduce $C_{\mathrm {out}}$ as a function of different capacitors in each structure to obtain a linear and continuous relation with tilt. Furthermore, we simulate each structure using COMSOL Multiphysics and then test the fabricated samples. Extracted results from analysis, simulation, and performance tests are in a good accordance. Obtained results reveal that the double capacitor structure has a high sensitivity of 32.2 mV/° in the range of ±90° while four-capacitor structure has a measurement range of ±180° (full turnover) with a sensitivity of 10.1 mV/°. High sensitivity, wide linear range besides simplicity of the structure, are advantages of the proposed inclination micro-sensor.

Measurement duration affects the calculation of whole body protein turnover kinetics but not between-day variability

BackgroundAssessment of whole body protein turnover (WBPT) can provide fundamental information about protein kinetics which underpins the conservation of lean tissue. Reliability and methodology studies on the measurement of WBPT are scarce. This study aimed to assess the effects of urine collection duration (9 versus 12 h) and the reproducibility of WBPT with the end product method calculated from ammonia as the end product. MethodsWBPT was assessed in 21 healthy participants (11M, 10F) on 2 test days. WBPT was assessed using the end product method with a single dose of 15N glycine with ammonia as end product in a postprandial state with 9 and 12-h urine collections. ResultsThe CV for protein flux averaged 10% and 12% for 9 and 12-h urine collections respectively. Protein flux, synthesis and balance were significantly higher and protein breakdown significantly lower with 9-h urine collections compared to 12-h collections (P < 0.01) and there was a trend towards increasingly greater overestimation of 9-h calculated WBPT kinetics with greater overall rates of WBPT. Correlations between the 9 and 12-h values were strong (r > 0.962, P < 0.001 for all variables). ConclusionsThe reproducibility of WBPT with ammonia as the end product was similar to previously reported reproducibility of the gold standard precursor technique. The use of a 12-h urine collection is more effective to achieve full turnover of the ammonia free amino acid (AA) pool.

Forecasting the evolution in the mixing regime of a deep subalpine lake under climate change scenarios through numerical modelling (Lake Maggiore, Northern Italy/Southern Switzerland)

The impact of air temperature rise is eminent for the large deep lakes in the Italian subalpine district, climate change being caused there by both natural phenomena and anthropogenic greenhouse-gases (GHG) emissions. These oligomictic lakes are experiencing a decrease in the frequency of winter full turnover and an intensification of stability. As a result, hypolimnetic oxygen concentrations are decreasing and nutrients are accumulating in bottom water, with effects on the whole ecosystem functioning. Forecasting the future evolution of the mixing pattern is relevant to assess if a reduction in GHG releases would be able to revert such processes. The study focuses on Lake Maggiore, for which the thermal structure evolution under climate change in the 2016–2085 period was assessed through numerical simulations, performed with the General Lake Model (GLM). Different prospects of regional air temperature rise were considered, given by the Swiss Climate Change Scenarios CH2011. Multiple realisations were performed for each scenario to obtain robust statistical predictions, adopting random series of meteorological data produced with the Vector-Autoregressive Weather Generator (VG). Results show that a reversion in the increasing thermal stability would be possible only if global GHG emissions started to be reduced by ~ 2020, allowing an equilibrium mixing regime to be restored by the end of the twenty-first century. Otherwise, persistent lack of complete-mixing, severe water warming and extensive effects on water quality are to be expected for the centuries to come. These projections can be extended to the other lakes in the subalpine district.

Amphibian skin microbiota exhibits temporal variation in community structure but stability of predicted Bd-inhibitory function.

Host-associated microbiomes are increasingly recognized to contribute to host disease resistance; the temporal dynamics of their community structure and function, however, are poorly understood. We investigated the cutaneous bacterial communities of three newt species, Ichthyosaura alpestris, Lissotriton vulgaris and Triturus cristatus, at approximately weekly intervals for 3 months using 16S ribosomal RNA amplicon sequencing. We hypothesized cutaneous microbiota would vary across time, and that such variation would be linked to changes in predicted fungal-inhibitory function. We observed significant temporal variation within the aquatic phase, and also between aquatic and terrestrial phase newts. By keeping T. cristatus in mesocosms, we demonstrated that structural changes occurred similarly across individuals, highlighting the non-stochastic nature of the bacterial community succession. Temporal changes were mainly associated with fluctuations in relative abundance rather than full turnover of bacterial operational taxonomic units (OTUs). Newt skin microbe fluctuations were not correlated with that of pond microbiota; however, a portion of community variation was explained by environmental temperature. Using a database of amphibian skin bacteria that inhibit the pathogen Batrachochytrium dendrobatidis (Bd), we found that the proportion of reads associated with 'potentially' Bd-inhibitory OTUs did not vary temporally for two of three newt species, suggesting that protective function may be maintained despite temporal variation in community structure.

Analytical models for a new turnover-based hybrid storage policy in unit-load warehouses

This paper considers a low-level unit-load warehouse employing single-deep storage lanes and a single-command manual storage and retrieval policy. Analytical travel distance models are developed for class-based and full turnover storage policies under across-aisle, within-aisle and a newly proposed hybrid product placement schemes. Our computational studies show that the analytical models developed in this paper are very accurate as compared to simulation results and a comparative study with a real-world warehouse case. Hybrid storage policies proposed in this paper outperform all other traditional storage policies. The paper also presents insights and simple design rules to warehouse practitioners.

Analytical models for pick distances in fishbone warehouse based on exact distance contour

The pick distance models for a unit load warehouse employing fishbone layout conventionally use semicircular approximation for distance contour which can result in significant error. This paper develops discrete and continuous pick distance models for fishbone layout under random, full turnover, and class-based storage policies based on exact polygonal distance contour. Class-based storage policy with three classes was found to give pick distance comparable to full turnover policy over a range of demand skews and warehouse shapes studied. The discrete and continuous models are compared considering finite storage space, aisle width and discontinues in the ABC curve for a real life data. The sensitivity of warehouse performance over a range of warehouse parameters is studied. We also outline a methodology for class-based storage design where class partitions can be derived for a warehouse of any dimension from the results of a unit area warehouse.

Mapping the core mass function to the initial mass function

It has been shown that fragmentation within self-gravitating, turbulent molecular clouds ("turbulent fragmentation") can naturally explain the observed properties of protostellar cores, including the core mass function (CMF). Here, we extend recently-developed analytic models for turbulent fragmentation to follow the time-dependent hierarchical fragmentation of self-gravitating cores, until they reach effectively infinite density (and form stars). We show that turbulent fragmentation robustly predicts two key features of the IMF. First, a high-mass power-law scaling very close to the Salpeter slope, which is a generic consequence of the scale-free nature of turbulence and self-gravity. We predict the IMF slope (-2.3) is slightly steeper then the CMF slope (-2.1), owing to the slower collapse and easier fragmentation of large cores. Second, a turnover mass, which is set by a combination of the CMF turnover mass (a couple solar masses, determined by the `sonic scale' of galactic turbulence, and so weakly dependent on galaxy properties), and the equation of state (EOS). A "soft" EOS with polytropic index $\gamma<1.0$ predicts that the IMF slope becomes "shallow" below the sonic scale, but fails to produce the full turnover observed. An EOS which becomes "stiff" at sufficiently low surface densities $\Sigma_{\rm gas} \sim 5000\,M_{\odot}\,{\rm pc^{-2}}$, and/or models where each collapsing core is able to heat and effectively stiffen the EOS of a modest mass ($\sim 0.02\,M_{\odot}$) of surrounding gas, are able to reproduce the observed turnover. Such features are likely a consequence of more detailed chemistry and radiative feedback.

Saving Ladle Control Model of Steel Ladle in Steelworks

Nowadays steelworks exists unmatched phenomenon of production rhythm between basic oxygen furnace and continuous caster, which need to saving ladle to ensure the caster casting, therefore the scientific-reasonable saving ladle control model of steel ladle could achieve energy saving significance. Based on the steel ladles of H steelworks as the research object, this article analyzes its operation process and time, matching model of basic oxygen furnace and caster. Through analyzing the relationship between the time of saving ladle and heats, the control model of saving ladle is constructed, which could calculate the reasonable time value of saving ladle, full ladle operation time and turnover cycle. Through applying Gantt chart to analysis and study the turnover rule of steel ladle, the turnover number control model of steel ladle is constructed. Satisfactory effects were obtained after applying the control model in production: saving number and turnover number were reduced, turnover ratio was increased, temperature drop was reduced.

Class-based storage with exact S-shaped traversal routeing in low-level picker-to-part systems

We consider a low level picker-to-parts system in a one-block warehouse with P/D point located at a corner point. We develop new and exact analytical models to estimate travel distance for random, full turnover and class-based storage in which a single picker follows an S-shaped traversal routeing policy. Our analytical results for random, full turnover and class-based storage follow corresponding simulations very closely with an accuracy of within 2% for the range of warehouse parameters considered. We also report the percentage improvement obtained by the optimal 3-class storage strategy over the random storage policy and the potential gain of this 3-class policy as compared to the full turnover policy. Further, we conduct a computational study to determine the optimal layout parameters for a warehouse with a 3-class optimal storage strategy for a given pick size per tour. Sensitivity analysis of pick travel distances with important warehouse parameters is also presented.

Inactivation of Met471Cys tyramine β-monooxygenase results from site-specific cysteic acid formation.

Tyramine β-monooxygenase (TβM), the insect homologue of dopamine β-monooxygenase, is a neuroregulatory enzyme that catalyzes the β-hydroxylation of tyramine to yield octopamine. Mutation of the methionine (Met) ligand to Cu(M) of TβM, Met471Cys, yielded a form of TβM that is catalytically active but susceptible to inactivation during turnover [Hess, C. R., Wu, Z., Ng, A., Gray, E. E., McGuirl, M. M., and Klinman, J. P. (2008) J. Am. Chem. Soc. 130, 11939-11944]. Further, although the wild-type (WT) enzyme undergoes coordination of Met471 to Cu(M) in its reduced form, the generation of Met471Cys almost completely eliminates this interaction [Hess, C. R., Klinman, J. P., and Blackburn, N. J. (2010) J. Biol. Inorg. Chem. 15, 1195-1207]. The aim of this study is to identify the chemical consequence of the poor ability of Cys to coordinate Cu(M). We show that Met471Cys TβM is ~5-fold more susceptible to inactivation than the WT enzyme in the presence of the cosubstrate/reductant ascorbate and that this process is not facilitated by the substrate tyramine. The resulting 50-fold smaller ratio for turnover to inactivation in the case of Met471Cys prevents full turnover of the substrate under all conditions examined. Liquid chromatography-tandem mass spectrometry analysis of proteolytic digests of inactivated Met471Cys TβM leads to the identification of cysteic acid at position 471. While both Met and Cys side chains are expected to be similarly subject to oxidative damage in proteins, the enhanced reactivity of Met471Cys toward solution oxidants in TβM is attributed to its weaker interaction with Cu(I)(M).

Sustainable storage assignment and dwell-point policies for automated storage and retrieval systems

Picking time reduction has been the traditional perspective for warehouse optimisation. When sustainability is considered, optimisation of warehouse operations should be read in terms of energy efficiency other than response time. Each location in the rack of an automated storage and retrieval system is associated with the value of energy consumed by the crane to reach it. Since picking performance strictly depends on storage location assignments, the time-based full turnover strategy is compared to the energy-based one. Three models of energy consumption are considered for traditional and new-generation cranes. Assignments are then compared in terms of dedicated zone shapes, time and energy performances within a given time horizon. Different shapes of the rack and product ABC curves are analysed. Dwell-point policies are also analysed from the new sustainable perspective, adding energy-saving performance to the traditional picking time reduction.

Basic concepts for designing renewable electricity support aiming at a full-scale transition by 2050

Renewable electricity supply is a crucial factor in the realization of a low-carbon energy economy. The understanding is growing that a full turn-over of the electricity sectors by 2050 is an elementary condition for avoiding global average temperature increase beyond 2 °C. This article adopts such full transition as Europe's target when designing renewable energy policy. An immediate corollary is that phasing-in unprecedented energy efficiency and renewable generation must be paralleled by phasing-out non-sustainable fossil fuel and nuclear power technologies. The double phasing programme assigns novel meaning to nearby target settings for renewable power as share of total power consumption. It requires organizing in the medium term EU-wide markets for green power, a highly demanding task in the present context of poorly functional markets in brown power. The EU Commission's 2007/2008 proposals of expanding tradable certificates markets were not based on solid analysis of past experiences and future necessities. The keystone of sound policies on renewable electricity development is a detailed scientific differentiation and qualification of renewable electricity sources and technologies, for measuring the huge diversity in the field. We provide but structuring concepts about such qualification, because implementation requires extensive research resources. Support for renewable electricity development is organized via feed-in prices or premiums, and via quota obligations connected to tradable green certificates. Green certificates are dependent on physical generated renewable power, but separable and no joint products. Contrary to conventional wisdom we argue their separation in cost analysis but firm linking during trade. A few graphs illustrate the importance of assigning qualities to different renewable power sources/technologies. Feed-in systems based on an acceptable qualification perform generally better than certificate markets imposing uniform approaches on a very diverse reality. For a similar reason, uniform and undifferentiated taxation of non-sustainable energy sources cannot replace renewable energy support schemes capable of differentiation.