Propylene Research Articles

Cardiac Radiofrequency Ablation Exacerbates Myocardial Injury through Pro-Inflammatory Response and Pro-Oxidative Stress in Elderly Patients with Persistent Atrial Fibrillation.

There is a need to assess myocardial damage after radiofrequency ablation of the pulmonary veins (PV) for persistent atrial fibrillation (PAF) in elderly patients. To evaluate oxidative stress, inflammatory response and myocardial damage in elderly patients with PAF after radiofrequency ablation of the PV. High-sensitivity troponin T (hsTnT), malondialdehyde-modified low-density lipoprotein (MDA-LDL), acrolein (ACR), lipid hydroperoxide (LHP), toll-like receptor 4 (TLR4), soluble growth stimulation expressed gene 2 (sST2), angiotensin II (Ang II) and myocardial blood flow (MBF) were determined before ablation and at 1, 3 and 5 months after radiofrequency ablation. The levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2 and Ang II were increased 3 months after ablations compared with before ablation and 1 month after ablation, respectively (P<0.001); they were further increased at 5 months after ablation compared with the 1- and 3-month groups, respectively (P<0.001). MBF was decreased in the 3 months group after ablations compared with before ablation and 1-month after ablation, respectively (P<0.001), and was further decreased in 5-months after ablations compared with 1-month and 3-month groups, respectively (P<0.001). Patients with epicardial monopolar radiofrequency ablation had higher levels of hsTnT, MDA-LDL, ACR, LHP, TLR4, sST2, Ang II and lower MBF than patients with endocardial monopolar and bipolar radiofrequency ablations, respectively (P<0.001). Monopolar radiofrequency ablation method could result in more myocardial injury than bipolar radiofrequency ablation. Oxidative stress and inflammatory response may be involved in cardiac radiofrequency ablation-induced myocardial injury, resulting in myocardial ischemia in elderly patients with PAF.

Design and simulation of 30 000 tons per year of cumene plant from natural gas field

Abstract The research considers the design and simulation of 30 000 tons per year of cumene plant using Aspen HYSYS as the simulation tool. The feed (material content) used is the characterized natural gas from Utorogu Gas Field with composition of 0.9019 methane, 0.0694 ethane, 0.0209 propane, 0.00361 n-butane, 0.00414 i-butane, 0.00005 n-pentane and 0.00007 i-pentane. The cumene plant consist of the cryogenic distillation column, de-hydrogenator (Continuous Stirred Tank Reactor), Alkylator (Plug Flow Reactor), storage tanks, separators, pumps, heat exchanger and mixers. The size/design models of basic plant units such as de-hydrogenator, alkylator, separators, storage tanks and distillation column were developed using the principles of mass and energy balance. The result of design or size specifications in terms of equipment diameter of basic plant units obtained from HYSYS simulation are 0.8 m and 0.319 m for the cryogenic and cumene columns; 1.931 m, 2.244 m and 1.366 m for the propane, propene and cumene storage tanks; 1.868 m and 2.076 m for the de-hydrogenator and alkylator; 1.931 m and 2.146 m for propene and cumene separators respectively. The power or capacity of propane and propene pumps configured in the plant are 0.02 kW and 0.005 kW respectively. The result of the reactor and distillation column thickness specification to withstand corrosion, pressure or stress during plant operation in terms of cylindrical shell and ellipsoidal doomed head are 17.36 mm and 4.31 mm respectively. The economic evaluation (overall cost) including the cost of utilities, catalyst, operating, and maintenance for entire plant is $ 3.004 M.

The Removal of Benzene and Toluene in Natural Gas with Cryogenic Liquid Propane: Effects and a Cyclic Purification Process

The Removal of Benzene and Toluene in Natural Gas with Cryogenic Liquid Propane: Effects and a Cyclic Purification Process

Cheese whey and dairy manure anaerobic co-digestion at psychrophilic conditions: Technical and environmental evaluation

Cheese whey (CW) and dairy manure (DM) are the main residues from the dairy industry, both of which can led to significant negative environment impacts if not properly managed. However, their combined anaerobic digestion represents an opportunity to obtain bioenergy and a stabilised material as a soil improver on the farm. Biochemical potential of methane (BMP) assays were carried out at psychrophilic conditions (20 °C) to analyse the influence on biomethane production of different CW:DM mixtures (% w/w) at different of inoculum-to-substrate ratios (ISR). Based on the BMP results, a life cycle assessment (LCA) of the cheese manufacturing process was carried out considering two scenarios (i) considering the current process, where propane gas and electricity are used for cheese production (ii) the incorporation of the biogas generated in the cheese production process in the company. BMP results showed that the best mixture between CW and DM was 65:35 (weight basis) at an organic load of 0.6 gVS/L (ISR of X). The LCA showed that CW and DM anaerobic digestion allowed to reduce the cheese manufacturing carbon footprint from through the substitution of propane by the biogas produced, changing from 5.5 to 3.1 kg CO2-eq/kg cheese produced, which indicates that according to the monthly production (633.6 kg) it would stop emitting about 1519 kg CO2-eq, i.e. a saving in terms of emissions of approximately 43,6% of the total currently generated.

Dynamics of nanocluster aerosol in the indoor atmosphere during gas cooking.

Nanocluster aerosol (NCA: particles in the size range of 1-3 nm) are a critically important, yet understudied, class of atmospheric aerosol particles. NCA efficiently deposit in the human respiratory system and can translocate to vital organs. Due to their high surface area-to-mass ratios, NCA are associated with a heightened propensity for bioactivity and toxicity. Despite the human health relevance of NCA, little is known regarding the prevalence of NCA in indoor environments where people spend the majority of their time. In this study, we quantify the formation and transformation of indoor atmospheric NCA down to 1 nm via high-resolution online nanoparticle measurements during propane gas cooking in a residential building. We observed a substantial pool of sub-1.5 nm NCA in the indoor atmosphere during cooking periods, with aerosol number concentrations often dominated by the newly formed NCA. Indoor atmospheric NCA emission factors can reach up to ∼1016 NCA/kg-fuel during propane gas cooking and can exceed those for vehicles with gasoline and diesel engines. Such high emissions of combustion-derived indoor NCA can result in substantial NCA respiratory exposures and dose rates for children and adults, significantly exceeding that for outdoor traffic-associated NCA. Combustion-derived indoor NCA undergo unique size-dependent physical transformations, strongly influenced by particle coagulation and condensation of low-volatility cooking vapors. We show that indoor atmospheric NCA need to be measured directly and cannot be predicted using conventional indoor air pollution markers such as PM2.5 mass concentrations and NO x (NO + NO2) mixing ratios.

Speed of sound measurements in (carbon monoxide + ethane) and (carbon monoxide + propane) gas mixtures at T = (260 to 350) K and up to 12 MPa

Speed of sound data are reported for (carbon monoxide + ethane) and (carbon monoxide + propane) mixtures in the gas region at mole fractions of carbon monoxide of 0.25, 0.5 and 0.75 in the temperature range from 273.15 K to 350 K for mixtures containing ethane, and compositions xCO = 0.5 and 0.75 at T = (260 to 350) K for mixtures with propane. Measurements are performed by means of a spherical acoustic resonator with an expanded relative uncertainty (k = 2) better than 250 parts in 106. Experimental data are fitted to a virial type equation, obtaining standard deviations within the uncertainty of the measurements, and the adiabatic coefficient as perfect gas is derived from this fitting. Finally, all these data are compared to GERG-2008 and AGA92-DC equations of state, which are used as reference in the gas industry.

DESIGN OF INQUIRY LEARNING MODEL INTEGRATED ETHNO-STEM FOR PROFILE ANALYZING THE AROMA COMPOUND FROM HERBAL TEA EXTRACT

The purpose of this research is to find a Design of an Inquiry Learning Model Integrated Ethno-Stem for Profile Analyzing the Aroma Compound from Herbal Tea Extract from tropical forest plants in Indonesia to accelerate student conservation literacy. This research is a basic research to find an Ethno-STEM integrated inquiry learning model and analysis of Aroma Compound profiles of herbal tea extracts from tropical forest plants in Indonesia. The research was conducted at the Department of Chemistry in the Natural Materials course. The research subjects are UNNES chemistry education students for the 2021/2022 academic year. The research instruments were tests, questionnaires, observation sheets, and aroma compound profile test data for herbal teas from Indonesian tropical forest plants. Trapping of aroma compound compounds from herbal teas from tropical forest plants uses Arduino sensors type MQ-9, MQ135, TGS 2602, and 2620. The stage of Development of the Ethno-STEM Integrated Inquiry Learning Model usees the Analysis, Design, Development, and Implementation. The results of the research found an Ethno-STEM integrated inquiry learning model with the Sudarmin stages. The results of the analysis of aroma compound profiles from tropical forest plants are hydrogen, propane, carbon monoxide (CO), alcohol, carbon dioxide (CO2), toluene, ammonia, acetone, heptane, and acid sulfide gas.

An assessment of recent thermal radiation model performance for propane gas fire experiments

In this article, the performance of five radiation models is investigated, including one conventional radiation model, that is, single-point source model, as well as four recently developed models, that is, a weighted multipoint source model, a cuboid flame model, a multicuboid flame model and a multicylinder flame model. The models are assessed in terms of the height of a target above flame base, the horizontal distance of target from flame source, heat release rate and size of burner. The estimations of the theoretical models are compared with propane-based experimental data with heat release rate ranging from 100 to 300 kW and assessed through numerical and graphical analysis. From the results obtained, the single-point source model outperformed the recently developed radiation models in estimating radiant heat received by an object located at a distance from the fire source, albeit it does exhibit some sensitivity to modifications in input parameters.

Utility of structural engineering on the monitoring of acrolein by aluminum nitride nano tube.

The study delves into the adsorption process of acrolein (AC) onto both an untainted and a titanium-doped aluminum nitride nanotube (AlNNT) using computations based on density functional theory. As AC approaches the pure AlNNT, it exhibits a calculated adsorption energy (Ead) of -5.3kcal/mol, underscoring the feeble nature of the adsorption. Furthermore, there has been very little change to the AlNNT's natural electrical characteristics. On the contrary, the introduction of titanium (Ti) enhances the performance of AlNNT, rendering it more susceptible and reactive to AC signals. Analyzing the conventional Gibbs free energy of formation computationally, we ascertain that replacing a nitrogen (N) atom with a titanium (Ti) atom within the aluminum nitride nanotube (AlNNT) structure presents a more advantageous prospect. Notably, there is a substantial alteration in the energy of adsorption (Ead) for AC as a Ti atom is incorporated onto the AlNNT surface, resulting in a shift from -5.3 to -24.6kcal/mol. Energy calculations and geometric optimizations were conducted utilizing the dispersion-augmented B3LYP method, known as B3LYP-D. In this approach, Grimme's dispersion term, referred to as the "D" term, was employed to account for dispersion forces. The basis set adopted was 6-31 + + G** (d), and all computational procedures were executed using the GAMESS software program. Following the incorporation of titanium (Ti), this adjustment leads to a substantial enhancement in sensing capability, reaching a value of 93.7. This indicates an improved electrical conductivity of the aluminum nitride nanotube (AlNNT). Remarkably, the Ti-doped AlNNT demonstrates the ability to detect AC distinctly, even in the presence of HCN, formaldehyde, ethanol, toluene, and acetone. The swift recovery process becomes evident as AC desorbs from the surface of Ti-doped AlNNT, with a calculated recovery time of 14.0s.

Appraising separation performance of MOF-808-based adsorbents for light olefins and paraffins

The development and design of efficient olefin/paraffin separation processes requires an understanding of the physicochemical properties of the adsorbent for target gas components. This paper presents experimental assessment of the adsorption characteristics of pristine and modified MOF-808s for ethane, ethene, propane and propene gases. The modification of MOF-808s was carried out using a post-synthesis approach, involving the use of two distinct types of ligands and subsequent addition of Cu metal. The pulse inverse gas chromatography technique at infinite dilution was employed to determine adsorption properties, including Henry's adsorption constants, adsorption enthalpies and entropies of the synthesized MOFs. The highest olefin/paraffin selectivity at 1 bar was identified in MOF-808-His-Cu, with selectivity values of 15.7 for ethene/ethane at 30 °C and 26.2 for propene/propane at 50 °C. This notable selectivity is probably attributable to the formation of π complexes between the olefin and Cu atoms present in the adsorbent. This is evidenced by the distinctive asymmetric chromatogram peak with a long tail, which aligns with their adsorption isotherm concavity. Depending on the molecule and the MOF-808 variant, different isotherm shapes and adsorption capacities were obtained.

Hydrogen sulfide protects against toxicant acrolein-induced ferroptotic cell death in Sertoli cells.

Acrolein (ACR) is a ubiquitous environmental pollutant and byproduct of lipid peroxidation that has been implicated in male infertility. However, the molecular mechanisms underlying ACR-induced toxicity in Sertoli cells remain unclear. Given its role in inducing oxidative stress, we examined whether ferroptosis, an iron-dependent form of regulated cell death, could mediate ACR toxicity in Sertoli cells. We also tested if hydrogen sulfide (H2S), which has antioxidant and ACR detoxifying properties, could protect Sertoli cells from ACR-induced ferroptosis. ACR exposure decreased Sertoli cell viability, increased protein carbonylation and p38 MAPK phosphorylation, indicating oxidative injury. ACR also depleted glutathione (GSH), downregulated the cystine importer SLC7A11, increased intracellular ferrous iron (Fe2+) and lipid peroxidation, suggesting activation of ferroptosis. Consistently, the ferroptosis inhibitor deferoxamine (DFO) markedly attenuates ACR-induced cell death. Further studies revealed that ACR-induced ferroptotic changes were prevented by exogenous H2S and exaggerated by inhibition of endogenous H2S production. Furthermore, H2S also suppressed GPX4 inhibitor RSL3-induced intracellular ACR accumulation and ferroptosis. In summary, our study demonstrates that ACR induces ferroptotic cell death in Sertoli cells, which can be prevented by H2S through multiple mechanisms. Targeting the H2S pathway may represent a therapeutic strategy to mitigate ACR-induced Sertoli cell injury and preserve male fertility.

Protective effects of EGCG on acrolein-induced Caenorhabditis elegans and its mechanism of life extension.

In this study, it was found that epigallocatechin-3-gallate (EGCG) could extend the lifespan of Caenorhabditis elegans (C. elegans) induced by 100 μM acrolein (ACR) at all test concentrations (300, 400, 500, 600, and 700 μM). Notably, 500 μM EGCG exhibited the most significant mean lifespan extension, increasing it by approximately 32.5%. Furthermore, 500 μM EGCG effectively reduced elevated levels of reactive oxygen species (ROS) and lipofuscin production caused by acrolein. It also bolstered the activity of antioxidant enzymes and mitigated malondialdehyde (MDA) levels compared to the ACR-only group. These effects appeared independent of dietary restrictions. Additionally, qPCR results revealed different changes in the transcription levels of 11 genes associated with antioxidative and anti-aging functions following EGCG treatment. At the expression level, GST-4::GFP, SOD-3::GFP and HSP-16.2::GFP exhibited an initial increase with ACR treatment followed by a decrease with EGCG treatment, while the expression pattern of these three GFPs remained consistent with the enzyme activity and transcription regulation level. EGCG treatment also reduced the nuclear localization of SKN-1 and DAF-16 in the MAPK and IIS pathways that were enhanced by ACR. Moreover, the longevity-promoting effects of EGCG were diminished or absent in 13 longevity gene-deletion mutants. In conclusion, EGCG demonstrates protective effects on ACR-induced C. elegans, with the IIS and MAPK pathways playing a critical role in enhancing resilience to ACR.

Photoredox chromium and cobalt dual catalysis for carbonyl allylation with butadiene via allyl radical intermediates

The allylation of aldehydes with dienes was achieved using cobalt and chromium catalysts through a metal-hydride hydrogen atom transfer (MHAT) pathway. The novel reaction resulted in the formation of various homo-allyl alcohols with excellent diastereoselectivity.

Electrochemical allylation of aldehydes and ketones with allylic alcohols

We disclose herein an electrochemical allylation of unactivated aldehydes and ketones with allylic alcohols. Various homoallylic alcohols can be obtained by treatment of aldehydes/ketones with allyl alcohols in a simple undivided cell.

Rapid lung ventilation MRI using parahydrogen-induced polarization of propane gas.

Proton-hyperpolarized contrast agents are attractive because they can be imaged on virtually any clinical MRI scanner, which is typically equipped to scan only protons rather than heteronuclei (i.e., anything besides protons, e.g., 13C, 15N, 129Xe, 23Na, etc.). Even though the lifetime of the proton spin hyperpolarization is only a few seconds, it is sufficient for inhalation and scanning of proton-hyperpolarized gas media. We demonstrate the utility of producing hyperpolarized propane gas via heterogeneous parahydrogen-induced polarization for the purpose of ventilation imaging in an excised rabbit lung model. The magnetization of protons in hyperpolarized propane gas is similar to that of tissue water protons, making it possible to rapidly perform lung ventilation imaging with a 0.35 T clinical MRI scanner. Here, we demonstrate the feasibility of rapid (2 s) lung ventilation MRI in excised rabbit lungs using hyperpolarized propane gas with a 1 × 1 mm2 pixel size using a 50 mm slice thickness, and a 1.7 × 1.7 mm2 pixel size using a 9 mm slice thickness.

Electrical tree properties of grafted polypropylene studied by electro-luminescence and free radical excitation analysis.

The electrical tree in grafted polypropylene (PP) is inhibited compared with that of pure PP. To understand the free radicals that are generated during the treeing process, we study the electron paramagnetic resonance (EPR) spectra. Additionally, to provide a clearer explanation of the suppression of electrical trees, this research uses electroluminescence (EL) and excitation computation. These methods help us to observe the movement of electrons and to understand the geometric and electronic structures involved. In pure PP, the energy required to excite the electrons is approximately the same as the band gap of PP while electrons are easier to be excited in grafted PP than in pure PP, because the band gap is narrower. As a result, though the electrical tree length is shorter in PP-g-MMA, the EPR signal is more intense because of the uneven distribution of electrons.

EFFICIENT PLANT GAS LEAKAGE DETECTION AND MONITORING SYSTEM BASED ON IOT INTEGRATION

In industrial areas, fire breakouts often stem from gas leaks within the surrounding environment. These leaks could be caused by faulty apparatus, inadequate maintenance, or human mistake either during handling or storage of flammable gases. The presence of combustible gases poses a significant risk, as they can ignite easily and escalate into large-scale fires, endangering both personnel and property within the industrial site. This research employs a compact detection device capable of identifying combustible gases like propane, LPG Gas, Carbon Monoxide, butane, and other hazardous gases. The device is designed to identify these gases quickly and accurately, aiding in ensuring safety in various environments such as industrial sites, homes, and workplaces. The leakage detector includes NODEMCU, gas sensors, buzzer, and LCD system. When harmful gases surpass acceptable thresholds, the micro-controller initiates a alerting SMS using Blynk server. The prototype emits a sound alert and illuminates LCDs to indicate the leaking gas. Gas concentration datais sent to Thinkspeak server for easy monitoring by plant personnel.

Diastereoselective allylation-based asymmetric total synthesis of 1,10-seco-guaianolides.

A Cr(II)-mediated Nozaki-Hiyama allylation of aldehydes with functionalized chiral allylbromolactone paved the way to easily access β-hydroxy-aryl/alkyl-α-methylene-γ-butyrolactones in good yields with high diastereoselectivities. A subsequent undemanding translactonization was orchestrated in the efficient first asymmetric total synthesis of two 1,10-seco-guaianolides as a valuable extension of the strategy developed.

Electrochemically modulated separation of olefin–paraffin gas mixtures in membrane electrode assemblies

Electrochemical flow cell demonstrates near-100% chemisorbing selectivity in separating propylene–propane gas mixtures, paving the way towards a sustainable olefin purifying process.

Photochemical carboborylation and three-component difunctionalization of α,β-unsaturated ketones with boronic acids via tosylhydrazones

The photochemical carboborylation of α,β-unsaturated tosylhydrazones with boronic acids gives tertiary allylboronates. A one pot sequence involving an aldehyde allylation provides a powerful three-component method for diversity oriented synthesis.