Current physical chemistry最新文献

{"title":"Human Bones Solubility in Seawater.","authors":"B. Krumgalz","doi":"10.2174/1877946812666220310143203","DOIUrl":"https://doi.org/10.2174/1877946812666220310143203","url":null,"abstract":"\u0000\u0000n January 1968, an Israeli submarine \"Dakar\" sank in the Mediterranean Sea. The Dakar’s wreckage was not found until May 1999, when it was located between the islands of Cyprus and Crete at depth more than 3,000 m by the Nauticos Corporation, the same company which found a British passenger liner \"Titanic\" that sank in the North Atlantic Ocean after it collided with an iceberg. The possibility to recover any existing remains of the crew members in the sunken submarine “Dakar” and to give them Jewish burial had been widely discussed in Israel.\u0000\u0000\u0000\u0000The human bones consist of mineral and organic matrixes. Therefore, the solubility of the bones in seawater will depend on the behavior of these two matrixes. The main mineral component of human bones is a calcium phosphate mineral which is similar in composition and structure to minerals within the apatite group. Thus, the human bones are rigid body tissue consisting of biological cells embedded in an abundant, hard intercellular material.\u0000\u0000\u0000\u0000The main objective is to study the possibility of solubility of human bones after prolonged time in deep waters.\u0000\u0000\u0000\u0000The solubility of minerals in natural waters can be calculated from thermodynamic considerations provided that the equilibrium constants are known, and ionic activity coefficients can be obtained. Using the approaches developed by Pitzer's scientific school for ionic activity coefficients calculations it was demonstrated in this article that neither hydroxyapatite nor fluorapatite can be dissolved in seawater.\u0000\u0000\u0000\u0000It is well known according to various publications, that no skeleton remains were found in the most cases of sunken ships wreckage in deep seawaters. The question is how this contradiction can be explained that if mineral constituents of human bones could not be dissolved in seawater, but no skeletons have been found in sunken ships being prolonged time in deep depths. We assume that the reason for this phenomenon that skeleton bonds in addition to mineral matrix contain organic constituents which can be dissolved in seawater due to various natural biological and chemical processes. After the dissolution of the organic constitutes of the bones, the bones remain could not be preserved as whole unites in sunk ships.\u0000\u0000\u0000\u0000It can be assumed that namely due to dissolution of the organic contents of human bones in seawater, human bodies’ remains cannot be found in most cases in sunken ships after prolonged time in deep waters\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45017567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical Transient Thermal Model for Predicting Cooldown Temperature in a Subsea Pipe-in-Pipe Flowline System","authors":"K. Shukla","doi":"10.2174/1877946812666220307093649","DOIUrl":"https://doi.org/10.2174/1877946812666220307093649","url":null,"abstract":"\u0000\u0000For the reliable operation of deep-water production systems transporting hydrocarbons, the critical flow assurance problems to manage are wax and hydrate formation and their deposition due to the heat transfer between the production system and surroundings. Wax and hydrate deposition can restrict the flow with significant production loss.\u0000\u0000\u0000\u0000The adequate thermal insulation of such systems can allow the retention of thermal energy in the production system to ensure that the fluid cooldown temperature remains above the wax and hydrate formation temperatures. This may provide sufficient time for taking the preventive measures during an emergency shut-in operation. The purpose of this paper is to predict the cooldown temperature of a subsea Pipe-in-Pipe flowline system transporting crude oil from the reservoir to the host facility using a recently developed transient thermal model. The model incorporates the energy redistribution inside the system through the internal temperature gradient and allows to determine the requirement of thermal insulation of the Pipe-in-Pipe system to retain sufficient heat before the fluid temperature falls below the hydrate and wax temperatures.\u0000\u0000\u0000\u0000The model results are compared with an industry accepted commercial simulator results to illustrate the accuracy of the model for emergency shut-in operations.\u0000\u0000\u0000\u0000With limited pipeline configurations and fluid properties, the model can successfully predict the requirements of thermal insulation and cooldown temperature efficiently and economically.\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47823427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simple Models of Charge-Transfer Reactivity","authors":"Roman F. Nalewajskj","doi":"10.2174/1877946812666220302150715","DOIUrl":"https://doi.org/10.2174/1877946812666220302150715","url":null,"abstract":"\u0000\u0000Finite-difference expressions for the chemical potential (negative electronegativity) and hardness (inverse softness) descriptors of molecular and reactive donor-acceptor systems are summarized and chemically “biased” (informed) and “unbiased” (uninformed) estimates of charge-transfer (CT) descriptors in A(acid)B(base)¬ systems are reexamined. The former recognizes the chemical characteristics of reactants and the chemical-potential discontinuity, while in the latter no prior knowledge of such kind is used. The biased chemical potential and fragment hardness descriptors are interpreted in terms of the frontier-electron orbitals, and equivalence of predictions in both treatments is demonstrated using the electronegativity-equalization principle. Two-state description of CT involves a statistical mixture of initial state NCT = 0 = A0, B0 of the polarized (mutually closed) reactants in R+ = (A+B+), and one of admissible final states for the full electron transfer, NCT = 1, in the forward B0A0 or reverse A0B0 directions, leading to ion-pairs B0A0 = NCT = 1 = A1, B+1 and A0B0 = NCT = 1 = A+1, B1. Parabolic interpolation between energies of the integral-N states identifies the process activation and reaction energies, predicts the equilibrium amount of CT and stabilization energy it generates\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46213255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AA, ACR and ACN Polymer (Synthetic Thickener) Formulation: \u0000Utilization on Reactive Printing of Cotton","authors":"C. R. Madhu","doi":"10.2174/1877946812666220301125133","DOIUrl":"https://doi.org/10.2174/1877946812666220301125133","url":null,"abstract":"\u0000\u0000Work investigated the integration and characterisation of a synthetic thickener, formulated by polymerisation of Acrylic acid, Acrylonitrile, and Acrylamide.\u0000\u0000\u0000\u0000Characterisation of the thickener confirmed with Fourier Transform Infrared spectral data, rheology and viscosity. The formulated thickener was utilized for preparation of reactive printing paste in different concentrations; printed on cotton, same procedure was undertaken for the study with guar gum and sodium alginate.\u0000\u0000\u0000\u0000The characteristics of prints such as K/S value, strength, fastness to washing, dry/wet rubbing, and light were assessed.\u0000\u0000\u0000\u0000The highest K/S value and excellent fastness properties were found in the samples, which were printed using formulated polymer.\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43709272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron Communications and Correlations in Subsystems‡","authors":"R. Nalewajski","doi":"10.2174/1877946812666220211150808","DOIUrl":"https://doi.org/10.2174/1877946812666220211150808","url":null,"abstract":"\u0000\u0000The quantum entanglement of molecular fragments in reactive systems is approached. The \"external\" (inter-fragment) and “internal” (intra-fragment) correlation energies are expressed in terms of the DFT average correlation holes resulting from the coupling constant integration of the scaled electron repulsion terms in the electronic Hamiltonian. Information networks in the local and configuration resolutions are examined, and their conditional entropy (covalency) and mutual information (iconicity) descriptors are summarized. The local channels in the single Slater determinant approximation of HF theory are explored in some detail. The multisite events in the bond system for the specified molecular state are tackled, cascade (bridge) propagations are examined, and the Fermi (exchange) correlation of HF theory is discussed. The partial density matrices of interacting fragments are introduced, and their role in shaping the ensemble averages of physical observables and effective communications within reactants is examined.\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46048537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can graphene act as a (noble) metal-free catalyst?.","authors":"U. Burghaus","doi":"10.2174/1877946812666220210142044","DOIUrl":"https://doi.org/10.2174/1877946812666220210142044","url":null,"abstract":"<jats:sec>\u0000<jats:title />\u0000<jats:p />\u0000</jats:sec>","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47811980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diazo-coupling reaction between 2-aminothiazole and thymol; Synthesis, DFT studies, and specific heat capacity calculations using TGA-DSC.","authors":"Z. Shah, F. Nouroz, S. Ejaz, A. Tayyeb","doi":"10.2174/1877946812666220126161309","DOIUrl":"https://doi.org/10.2174/1877946812666220126161309","url":null,"abstract":"\u0000\u0000This study was aimed to investigate the role of E2F1 in breast cancer biology.\u0000\u0000\u0000\u0000Expression of E2F1, a transcription factor of many oncogenes and tumor suppressor genes, is lowered in several malignancies including breast carcinoma.\u0000\u0000\u0000\u0000In the present study we analyzed the status of E2F1 expression in association with diverse attributes of breast malignancy and its impact on cancer progression.\u0000\u0000\u0000\u0000For this purpose we used various freely available online applications for gene enrichment, expression and methylation analysis, to extract mutation based E2F1 map, to measure E2F1 drug sensitivity and to determine E2F1 association with damage response proteins.\u0000\u0000\u0000\u0000Results revealed tissue specific regulatory behavior of E2F1. Moreover, the key role of E2F1 in the promotion of metastasis, stem cell mediated carcinogenesis, estrogen mediated cell proliferation and cellular defense system has therefore highlighted it as metaplastic marker and hot member of key resistome pathways.\u0000\u0000\u0000\u0000The information thus generated can be employed for future implications in devising rational therapeutic strategies. Moreover, this study has provided a more detailed insight into the diagnostic and prognostic potential of E2F.\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46792596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DFT Studies and Quantum Chemical Calculations of Benzoyl Thiourea Derivatives Linked with Morpholine and Piperidine for the Evaluation of Antifungal Activity","authors":"R. K. Dongare, Shaukatali N. Inamdar, R. Tigote","doi":"10.2174/1877946812666220111141742","DOIUrl":"https://doi.org/10.2174/1877946812666220111141742","url":null,"abstract":"\u0000\u0000Herein, we report the density functional study of benzoyl thiourea derivatives linked to morpholine and piperidine to evaluate their antifungal activity. Overall six compounds BTP 1-3 and BTM 4-6 were optimized with DFT using the B3LYP method with 6-31G(d,p) basis set. The molecular geometry, bond lengths, bond angles, atomic charges and HOMO-LUMO energy gap have been investigated. The structural parameters have been compared with the reported experimental results and structure- antifungal activity relationship is explored in details. The calculated results from DFT were discussed using all Quantum chemical parameters of the compounds.\u0000\u0000Introduction: Benzoyl thiourea derivatives linked with morpholine and piperidine were reported to have good antifungal activity.\u0000\u0000Objective: To find the correlations between the quantum chemical calculations and the antifungal activity for the benzoyl thiourea derivatives linked with morpholine and piperidine.\u0000\u0000Method: Optimization was carried out with DFT using B3LYP method utilizing 6-31G(d,p) basis set.\u0000\u0000Results: A good correlation between the quantum chemical calculations and the antifungal activity for the benzoyl thiourea derivatives linked \u0000with morpholine and piperidine was found.\u0000\u0000Conclusion: The DFT study of benzoyl thiourea derivatives linked to morpholine and piperidine was evaluated for their antifungal activity and it showed good correlations of activity with the quantum chemical parameters.\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48795806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Physical Chemistry to Investigate Probiotic-Prebiotic Mixed Systems","authors":"H. Razafindralambo","doi":"10.2174/1877946812666220111142213","DOIUrl":"https://doi.org/10.2174/1877946812666220111142213","url":null,"abstract":"<jats:sec>\u0000<jats:title />\u0000<jats:p />\u0000</jats:sec>","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44389219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibition of Fenton Reaction of Glucose by Alcohols and Tetrahydrofuran in Catalytic Concentrations. Calculation of the Stability Constants of ROH/Fe2+ Complexes","authors":"A. Vitale, E. Bernatene, A. Pomilio","doi":"10.2174/1877946812666211217152703","DOIUrl":"https://doi.org/10.2174/1877946812666211217152703","url":null,"abstract":"\u0000\u0000 The Fenton reaction is of growing interest due to its primary function in bodily processes and industrial waste disposal. However, the effects of alcohol on this reaction have not been addressed. Therefore, we analyze for the first time the role that catalytic concentrations of alcohols play in the Fenton reaction.\u0000\u0000\u0000\u0000\u0000The Fenton reaction was carried out by measuring oxidation-reduction potential and pH monitoring under dark conditions to avoid photochemical reactions. The reaction end point was established using the first derivative of plotting potential versus time. This point was also checked by the dichromate test for hydrogen peroxide detection. \u0000Gas-liquid chromatography was used to measure alcohol content. The Fenton reaction of glucose was performed first, and then each alcohol, including ethanol, methanol, iso-propanol, and ter-butanol, was added separately in catalytic amounts, as well as the cyclic ether tetrahydrofuran. The reaction rate constants and the stability constants of each complex formed were measured. \u0000\u0000\u0000\u0000Alcohols were shown to inhibit the Fenton reaction by forming iron-alcohol complexes. An iron-tetrahydrofuran complex was also formed. The crucial oxygen role in the functional group of alcohols and ethers is supported by a reaction with tetrahydrofuran. These results also explain the difficulties in the disposal of sugar-enriched alcoholic industrial effluents.\u0000\u0000\u0000\u0000\u0000Our findings show that alcohols, such as ethanol, methanol, iso-propanol, and ter-butanol at catalytic concentrations, slow down the Fenton reaction due to decreased iron availability by forming iron(II)-alcohol complexes. The method is also useful for calculating stability constants for iron-alcohol and iron-tetrahydrofuran complexes, which are not otherwise easy to assess. \u0000\u0000","PeriodicalId":89671,"journal":{"name":"Current physical chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48854505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}