scholarly journals Water Activity Prediction in Sugar and Polyol Systems Using Theoretical Molecular Descriptors

2021 ◽  
Vol 22 (20) ◽  
pp. 11044
Author(s):  
Antonio Zuorro
Keyword(s):  
Water Activity ◽  
Binary Systems ◽  
Molecular Descriptors ◽  
Experimental Information ◽  
Activity Prediction ◽  
Information Index ◽  
Molecular Features ◽  
New Strategy ◽  
Key Factor ◽  
Positive Results

Water activity is a key factor in the development of pharmaceutical, cosmetic, and food products. In aqueous solutions of nonelectrolytes, the Norrish model provides a simple and effective way to evaluate this quantity. However, it contains a parameter, known as the Norrish constant, that must be estimated from experimental data. In this study, a new strategy is proposed for the prediction of water activity in the absence of experimental information, based on the use of theoretical molecular descriptors for characterizing the effects of a solute. This approach was applied to the evaluation of water activity in the presence of sugars (glucose, fructose, xylose, sucrose) and polyols (sorbitol, xylitol, glycerol, erythritol). The use of two descriptors related to the constitutional and connectivity properties of the solutes was first investigated. Subsequently, a new theoretical descriptor, named the global information index (G), was developed. By using this index, the water activity curves in the binary systems were reconstructed. The positive results obtained support the proposed strategy, as well as the possibility of including, in a single information index, the main molecular features of a solute that determine its effects on water activity.

scholarly journals Charged aerosol detector response modeling for fatty acids based on experimental settings and molecular features: a machine learning approach

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruben Pawellek ◽  
Jovana Krmar ◽  
Adrian Leistner ◽  
Nevena Djajić ◽  
Biljana Otašević ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Mobile Phase ◽  
Molecular Descriptors ◽  
Attribute Selection ◽  
Selection Strategy ◽  
Detector Response ◽  
Experimental Conditions ◽  
Molecular Features ◽  
Charged Aerosol ◽  
Charged Aerosol Detector

AbstractThe charged aerosol detector (CAD) is the latest representative of aerosol-based detectors that generate a response independent of the analytes’ chemical structure. This study was aimed at accurately predicting the CAD response of homologous fatty acids under varying experimental conditions. Fatty acids from C12 to C18 were used as model substances due to semivolatile characterics that caused non-uniform CAD behaviour. Considering both experimental conditions and molecular descriptors, a mixed quantitative structure–property relationship (QSPR) modeling was performed using Gradient Boosted Trees (GBT). The ensemble of 10 decisions trees (learning rate set at 0.55, the maximal depth set at 5, and the sample rate set at 1.0) was able to explain approximately 99% (Q2: 0.987, RMSE: 0.051) of the observed variance in CAD responses. Validation using an external test compound confirmed the high predictive ability of the model established (R2: 0.990, RMSEP: 0.050). With respect to the intrinsic attribute selection strategy, GBT used almost all independent variables during model building. Finally, it attributed the highest importance to the power function value, the flow rate of the mobile phase, evaporation temperature, the content of the organic solvent in the mobile phase and the molecular descriptors such as molecular weight (MW), Radial Distribution Function—080/weighted by mass (RDF080m) and average coefficient of the last eigenvector from distance/detour matrix (Ve2_D/Dt). The identification of the factors most relevant to the CAD responsiveness has contributed to a better understanding of the underlying mechanisms of signal generation. An increased CAD response that was obtained for acetone as organic modifier demonstrated its potential to replace the more expensive and environmentally harmful acetonitrile.

scholarly journals Research on Characteristics of Chinese Herbal Medicine Compounds Based on Bisecting k-Means Algorithm

2020 ◽  
Author(s):  
Yushu Wu ◽  
Fenfen Xie ◽  
Lu Wang ◽  
Shoude Zhang ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Chinese Herbal Medicine ◽  
Clustering Algorithm ◽  
Molecular Descriptors ◽  
Molecular Data ◽  
Experimental Comparison ◽  
Chemical Components ◽  
Chinese Herbal ◽  
Molecular Features ◽  
Molecular Compounds

The properties of Chinese Herbal Medicine (CHM) are determined to some extent by the properties of their molecular compounds, so it is of great significance to study CHM from the perspective of molecular compounds. In this paper, the clustering algorithm in data mining is used to study the relationship between the properties of CHM and its chemical components. Firstly, the molecular data are collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, and the data set is preprocessed to extract the key molecular descriptors of chemical components. Secondly, the k-means algorithm and the Bisecting k-means algorithm are used to cluster the chemical components based on the CHM molecular descriptors, and the representative molecular features of the cold and hot CHM are extracted; finally, through experimental comparison, it is found that the clustering results obtained by Bisecting k-means algorithm are better. The clustering results show that the average values of molecular composition descriptors and charge descriptors in cold CHM are significantly higher than those in hot CHM. Therefore, the properties of CHM may be affected by molecular structure and molecular charge properties.

Thermodynamic Calculation of Phase Equilibria in the Mn-RE (RE=Nd, Gd, Dy) Binary Systems

2017 ◽  
Vol 898 ◽  
pp. 1036-1041
Author(s):  
M.H. Rong ◽  
S.D. Lin ◽  
Jiang Wang ◽  
H.Y. Zhou ◽  
G.H. Rao
Keyword(s):  
Magnetic Properties ◽  
Thermodynamic Properties ◽  
Phase Equilibria ◽  
Thermodynamic Calculation ◽  
Binary Systems ◽  
Ternary Systems ◽  
Experimental Information ◽  
Calphad Method ◽  
Self Consistent ◽  
Ternary Intermetallic Compounds

Ternary intermetallic compounds with rare earth elements and transition metals in the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems show interesting magnetic properties. As key sub-binary systems of the RE-Mn-X (X=Si, Ge, Sn etc.) ternary systems, the information of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems are indispensable to explore the RE-Mn-X (X=Si, Ge, Sn etc.) alloys with better magnetic properties. In this work, the experimental data of phase equilibria and thermodynamic properties of the Mn-RE (RE=Nd, Gd, Dy) binary systems in the published literature were reviewed. Based on the available experimental information, thermodynamic calculation of phase equilibria of the Mn-RE (RE=Nd, Gd, Dy) binary systems was performed using the CALPHAD method. As a result, further experimental investigation and thermodynamic optimization would be still necessary in order to develop the self-consistent and compatible thermodynamic database of the RE-Mn-based alloy systems.

scholarly journals Sampling Frequency Is a Key Factor to the Efficient Actuation of the Phytohormones in the Increase of Biomass and Macromolecules Production by Spirulina (Arthorspira)

2021 ◽  
Author(s):  
Jéssica Teixeira Silveira ◽  
Ana Priscila Centeno Rosa ◽  
Jorge Alberto Vieira Costa
Keyword(s):  
Large Scale ◽  
Production Capacity ◽  
Biomass Accumulation ◽  
Sampling Frequency ◽  
Cultivation System ◽  
New Strategy ◽  
Key Factor ◽  
Daily Sampling ◽  
Cultivation Strategy ◽  
Operational Aspects

Abstract Application of microalgae in industries is limited by their low biomass production and low macromolecule content. Phytohormones are being studied to solve these problems, however is necessary to define conditions that enhance the results for this kind of cultivation strategy. The increasing of the contact time between substances and cells can be a factor of the improvement in the phytohormone uptake by microalgae. We hypothesize that by decreasing the sampling frequency for monitoring culture parameters, we would also be interfering less in the uptake of phytohormones by microalgae. Therefore, the present study aimed to investigate the influence of sampling frequency on the production of biomass and biomolecules of Spirulina sp. LEB 18 in cultivations supplemented with trans-zeatin and indole-3-acetic acid (IAA). Treatments with lower sampling frequency and supplementation of 1 mg L− 1 IAA enhanced biomass accumulation by 75 %, carbohydrate content by 50 %, and protein content by 30 % as compared to control experiment daily sampling. In addition, sampling every 10 days with 0,01 mg L− 1 IAA supplementation increased the lipid content by 51 % as compared with the experiment without phytohormone and daily sample removal. Therefore, we developed a new strategy to supplement phytohormones and improve microalgal production. This investigation presented a cultivation system efficient, which can be easy to implement in industries because of no need to change the operational aspects of the cultivation. Furthermore, the strategy will can be very useful to enhance the production capacity of microalgae on a large-scale.

scholarly journals Comparative empirical analysis on the effect of mortgage loan on capital adequacy ratio

2017 ◽  
Vol 5 (3) ◽  
pp. 6
Author(s):  
Yusuf Dinç
Keyword(s):  
Credit Risk ◽  
Negative Impact ◽  
Capital Adequacy ◽  
Mortgage Loan ◽  
Basel Accord ◽  
Main Indicator ◽  
Capital Adequacy Ratio ◽  
Key Factor ◽  
Conventional Banks ◽  
Positive Results

Capital adequacy ratio is the main indicator for banks to proceed with their operations. Standards for the calculation of the ratio are based on Basel Accord. Key factor for the calculation is credit risk. Credit risk is a function of credit and collateral type. In this case, mortgage has lower risk weight based on its collateral structure on credit risk. This research evaluates the effects of mortgages on capital adequacy ratio to understand the effects of collateral based credits. The findings show positive results between capital adequacy ratio and mortgages of participation banks. However, mortgages have negative impact on capital adequacy ratio of conventional banks. Participation and conventional banks of Turkey are compared on linear regression to analyse the effects of mortgages on capital adequacy ratio. Results are important for further research and professionals.

Port Single Window and Logistics Single Window

2017 ◽  
pp. 316-333
Author(s):  
José Carlos Dias Simão ◽  
Pedro Fernandes da Anunciação
Keyword(s):  
Information Management ◽  
Public Interest ◽  
Relational Model ◽  
Maritime Transport ◽  
The Public ◽  
Key Factor ◽  
Strategic Issue ◽  
Area Of Influence ◽  
Positive Results

A port is a confluence point for the various means of transport, responsible for the handling of the industries and other sort of companies goods located within their area of influence, which is called hinterland. The agile handling of ships and cargoes is a key factor for the competitiveness of a port, and the information management is ever more a strategic issue within this scope. Nevertheless, the different features of the various means of transport, the multiple players involved in port intermodality and logistics, as well as the cultural, technological and procedures simplification asymmetries of both the authorities representing the public interest inside the port and the private parties involved in the port business offer difficulties to the development of an agile and electronic integrated relational model. The “Single Window” philosophy implemented for the management of port information has been achieving very positive results, as far as maritime transport concerns (a sector with very specific characteristics), being absolutely imperative to apply this philosophy to all the means of transport and port logistics. The agility of information in intermodality is still an incipient reality, and the present project takes a careful look at this problematic. Our case-study is Port of Sines and we will make an analysis of the present situation and present a possible development to new conceptual developments in this area.

Prediction of Solid Solution Formation among Chemically Similar Molecules Using Calculation of Lattice and Intermolecular Interaction Energy

2020 ◽  
Vol 850 ◽  
pp. 54-59 ◽  
Author(s):  
Kristaps Saršūns ◽  
Agris Bērziņš
Keyword(s):  
Interaction Energy ◽  
Intermolecular Interaction ◽  
Solid Solutions ◽  
Binary Systems ◽  
Experimental Information ◽  
X Ray Diffraction ◽  
Intermolecular Interaction Energy ◽  
Scanning Calorimetry ◽  
Nitrobenzoic Acid ◽  
Crystallization Experiments

Several 2-substituted 4-nitrobenzoic acid (NBA) derivatives such as 2-chloro-4-nitrobenzoic acid (2C4NBA), 2-methyl-4-nitrobenzoic acid (2CH34NBA) and 2-hydroxy-4-nitrobenzoic acid (2OH4NBA) were selected as model compounds because of their availability and chemically similar structures, in which the different group/atom (R) does not significantly affect the dominant intermolecular interactions – hydrogen bonds formed by the carboxylic group [1]. Quantum chemical calculations of lattice and intermolecular interaction energy were carried out to identify possible factors, which could be, used in prediction of the formation of solid solutions (SS) in binary systems of chemically similar molecules, in this case - various nitrobenzoic acid derivatives. Meanwhile, crystallization experiments were used to determine the experimental information about formation of solid solutions. The obtained crystalline phases were characterized by combined use of powder X-ray diffraction (XRPD) and differential scanning calorimetry/thermogravimetry (DSC/TG) [2].

scholarly journals Short-Term Reservoir System Operation for Flood Mitigation with 1D Hydraulic Model

10.29007/jqtw ◽  
2018 ◽  
Author(s):  
Thanh Hao Nguyen ◽  
Philippe Gourbesville ◽  
Ngoc Duong Vo
Keyword(s):  
Reservoir Operation ◽  
Energy Demand ◽  
Flood Disaster ◽  
Artificial Reservoir ◽  
Reservoir System ◽  
Hydropower Plants ◽  
New Strategy ◽  
Key Factor ◽  
Negative Impacts ◽  
The Impact

Artificial reservoir operation is expected to affect significantly the flood disaster. It becomes more complicatedly towards the large systems where the operation of each reservoir has to meet fully with the systematic objective. Consequently, reservoir operation optimization is considered as a key factor to control the flood disaster at downstream area. Due to energy demand, more than twenty hydropower plants have been constructed over 10,350 km2 of Vu Gia Thu Bon river catchments. The system has contributed importantly for economy development when provides annually a green electrical quantity up to 6 Terawatt-hour (TWh). Therefore, operation of system has still several limitations. It is judged to make the natural disaster increase in recent years. In order to reduce negative impacts of artificial reservoir system, four largest reservoirs are selected to simulate in this study. The simulation is carried out via Structure Control (SO) module of MIKE 11 model (DHI). The performance of operational scenario is demonstrated via the relation with the water level at two stations. The study is expected to provide an overview of the impact of artificial reservoir operation to flood disasters, as well as propose a new strategy to operate optimally the hydropower plants in Vu Gia Thu Bon catchments.

scholarly journals ANALISIS KEBIJAKAN HUTAN RAKYAT KEMITRAAN YANG BERKELANJUTAN

2021 ◽  
Vol 18 (2) ◽  
pp. 117-128
Author(s):  
Mahawan Karuniasa ◽  
◽  
Niken Probo Laras ◽  
Keyword(s):  
Policy Implementation ◽  
Evaluation Method ◽  
Standing Stock ◽  
Research Area ◽  
Raw Material ◽  
Low Grade ◽  
Private Forest ◽  
New Strategy ◽  
Key Factor ◽  
Hierarchy Process

Private forest partnership has been considered as a new strategy in dealing with conventional socio-economic model problem of the industrial wood raw material sustainability supply. As a new strategy to address the issue of sustainability of industrial wood supply, synergy is needed between forest farmer groups and timber-based industry through private forest partnership schemes. This research aims to analyze private forest partnership policy and its implementation in terms of cooperation aspects in order to formulate a sustainable private forest partnership policy. Content analysis was used to identify all policies related to private forestry partnerships, while policy implementation was analyzed by using formal evaluation method. The descriptive method was implemented to analyze standing stock managemet, and Analytical Hierarchy Process (AHP) as a method to formulate the concept of sustainable private forest partnership policy. The results showed that private forest partnership policy now is more focused on production facilities and infrastructure aspect. The level of policy implementation in research location is at a low grade, only reached 16.28%, while 43.75% of the private forest partnerships in the research area are not sustainable due to low potential of standing stock. This research proved that fostering the farmers is a key factor to develop sustainable private forest partnership policy.

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