Rapid Injection Research Articles

INFLUENCE OF ALUMINA PARTICLES (AL2O3) ON PHYSICO-MECHANICAL BEHAVIOR OF ADDITIVE MANUFACTURING- DLP RESIN USED FOR RAPID TOOLING

Over the past decade, additive manufacturing (AM) has gained considerable recognition in rapid tool manufacturing owing to its notable advantages. For the rapid injection mold manufacturing by the DLP-AM method, the most important subject that should be focused on is the photopolymer resin, as the 3D printed mold must withstand the stresses and temperatures encountered by the injection pressure and temperature of the molten plastic. This study aimed to investigate the effect of adding alumina (Al2O3) powder on the properties of a DLP-AM photopolymer. For this aim, 2 and 4 wt.% Al2O3 were added to a photopolymer resin, and 3D-printed samples were produced by DLP. Several physico-mechanical properties were studied compared to the pure polymer. The results indicated that as the Al2O3 content increased, the void fraction, volumetric heat capacity, wear resistance, tensile and flexural strength, all decreased. In contrast, as the Al2O3 wt.% increased, so did the flexural strain, impact strength, hardness, and thermal conductivity. This study showed that injection molding cycle times can be shortened considerably due to this benefit, which would be beneficial for quick molding applications. Keywords: Rapid tool manufacturing, polymer composites, 3D printing, alumina, Al2O3, photopolymer, additive manufacturing.

Influence of Menthol Infusion on Esophageal Peristalsis in Patients With Ineffective Esophageal Motility.

Activation of the cold receptor, transient receptor potential melastatin 8 (TRPM8) by menthol inhibits esophageal secondary peristalsis in healthy adults. Ineffective esophageal motility (IEM) is common. This study is to evaluate the effects of acute infusion of menthol on esophageal peristalsis in patients with IEM. Twenty patients with IEM (males 11, mean age 36) were studied for esophageal peristalsis using high-resolution manometry. All participant had primary peristalsis performed with 10 water swallows and secondary peristalsis generated with 10 rapid air injections of 20 mL via mid-esophageal infusion port. Two different sessions by randomly performing acute administration of placebo or menthol (3 mM) were used for testing their effects on esophageal peristalsis. Menthol infusion had no effects on distal contractile integral (P = 0.471), distal latency (P = 0.58), or complete peristalsis (P = 0.251). Menthol infusion did not change basal lower esophageal sphincter pressure (P = 0.321), esophagogastric junction contractile integral (P = 0.758), or integrated relaxation pressure (P = 0.375) of primary peristalsis, but reduced upper esophageal sphincter pressure (P = 0.037). Infusion of menthol significantly reduced the frequency of secondary peristalsis for air injects of 20 mL (P = 0.002), but did not affect distal contractile integral of secondary peristalsis for air injections of 20 mL. This work has suggested that activation of TRPM8 by menthol can attenuate mechanosensitivity of secondary peristalsis in response to rapid air distension regardless of the presence of IEM.

Evaluation of Flow Resistance Increase Due to Fouling in Cooling Channels: A Case Study for Rapid Injection Molding

Abstract After certain time of operation, the cross-section of cooling channels in injection molds may decrease due to fouling, i.e. the formation and growth of a layer of sediment on the walls of the channels. This phenomenon can decrease heat transfer or ultimately completely block the flow of coolant in the channel. The build-up of the sediment layer increases the temperature of the mold, which may consequently reduce the quality of the plastic products. In the paper, the pressure drop in a typical cooling channel of an injection mold is investigated, as well as the effect of the sediment layer on the coolant flow in an example channel with a diameter of 10 mm. A novelty is the developed analytical model that allows determining the pressure drop in the case when two perpendicular channels do not intersect centrally due to manufacturing inaccuracies that often happen when drilling long channels in hard materials. The proposed hydraulic model allows for calculation of the coolant pressure drop in real injection molds and can be an alternative to time-consuming CFD simulations. The presented results of measurements and the hydraulic model calculations show that the thickness of the sediment layer in the tested channel of the actual injection mold can be up to 1.7 mm. The hydraulic model proposed in this work allows for the estimation of the thickness of the sediment layer and the identification of places of local increase in the coolant velocity, where self-cleaning of the channels in injection molds may take place.

Compositional simulation of coupled transport mechanisms in fractured-vuggy underground gas storage: A case study of LWC in the Sichuan Basin

Compositional models were built to simulate the underground gas storage (UGS) operation, which is characterized by multiple cycles of rapid injection and production. Based on the validated model of the fractured-vuggy underground gas storage Lao Weng-Chang (LWC), this study evaluated the individual and coupling effects of stress sensitivity, relative permeability hysteresis, and high-speed non-Darcy flow on UGS operation. It was found that stress sensitivity is the main controlling factor behind the reduced working gas volume, and it led to a 6.07% decline in working gas volume. Relative permeability hysteresis is the determining factor for the storage capacity, and it led to a 9.05% decline in storage capacity. The high-speed non-Darcy flow only led to a 0.16% reduction in storage capacity but led to a 4.19% decline in working gas volume. A higher stress sensitivity coefficient and increased residual gas saturation both lead to greater losses in both storage capacity and working gas volume. Coupling stress sensitivity and relative permeability hysteresis would have a more pronounced effect on working gas volume than when considered individually. Considering the high-speed non-Darcy flow further decreases working gas volume. The gas production per unit pressure drop will also decrease with the increasing Reynolds number, and there exists a critical value of Re where the decrease significantly accelerates.

Omnidirectional Energetic Electron Fluxes From 150 to 20,000 km: An ELFIN‐Based Model

AbstractThe strong variations of energetic electron fluxes in the Earth's inner magnetosphere are notoriously hard to forecast. Developing accurate empirical models of electron fluxes from low to high altitudes at all latitudes is therefore useful to improve our understanding of flux variations and to assess radiation hazards for spacecraft systems. In the present work, energy‐ and pitch‐angle‐resolved precipitating, trapped, and backscattered electron fluxes measured at low altitude by Electron Loss and Fields Investigation (ELFIN) CubeSats are used to infer omnidirectional fluxes at altitudes below and above the spacecraft, from 150 to 20,000 km, making use of adiabatic transport theory and quasi‐linear diffusion theory. The inferred fluxes are fitted as a function of selected parameters using a stepwise multivariate optimization procedure, providing an analytical model of omnidirectional electron flux along each geomagnetic field line, based on measurements from only one spacecraft in low Earth orbit. The modeled electron fluxes are provided as a function of ‐shell, altitude, energy, and two different indices of past substorm activity, computed over the preceding 4 hr or 3 days, potentially allowing to disentangle impulsive processes (such as rapid injections) from cumulative processes (such as inward radial diffusion and wave‐driven energization). The model is validated through comparisons with equatorial measurements from the Van Allen Probes, demonstrating the broad applicability of the present method. The model indicates that both impulsive and time‐integrated substorm activity partly control electron fluxes in the outer radiation belt and in the plasma sheet.

The Need for Separate Testing with Acetylcholine for the Assessment of Endothelial Dysfunction and Coronary Artery Spasm.

Intracoronary acetylcholine (ACH) testing is clinically useful to diagnose the presence of the coronary vasomotor disorders coronary endothelial dysfunction and coronary epicardial/microvascular spasm. In Western countries, continuous intracoronary injection of ACH for 2-3 minutes without a pacemaker is the usual method, while rapid injection of ACH for 20-30 seconds with a pacemaker is the traditional procedure in Japan. Coronary microvascular spasm is often observed in Western populations, whereas coronary epicardial spasm is frequently seen in Japanese subjects. Methodological differences between Western and Japanese protocols may lead to the opposite prevalence of coronary vasomotor disorders. This article discusses the optimal method for diagnosing endothelial dysfunction and epicardial/microvascular spasm based on previous reports, and compares intracoronary ACH testing performed by Western cardiologists with that by Japanese physicians.

A simple and rapid batch injection analysis method with amperometric detection for determination of azithromycin in pharmaceutical tablets

A simple and rapid batch injection analysis method with amperometric detection for determination of azithromycin in pharmaceutical tablets

Relevance of ineffective esophageal motility to striated esophageal muscle contraction: Studies with high-resolution manometry.

Striated esophageal muscle contraction (SEC) is important for pharyngeal swallowing and deglutition augmentation against aspiration. Its clinical relevance is unclear in patients with ineffective esophageal motility (IEM). In this study, we aimed to characterize and compare SEC in consecutive patients with and without IEM. All eligible patients were evaluated for SEC, primary and secondary peristalsis using high-resolution manometry (HRM) with one mid-esophageal injection port. Primary peristalsis was assessed with 10 5-mL liquid swallows and multiple rapid swallows (MRS), while secondary peristalsis was performed with rapid air injections of 20 mL. All peristatic parameters of HRM were measured, and SEC and its contractile integral (SECI) were evaluated. One hundred and forty patients (59.3% women, mean age 46.1 ± 13.1 years) were included. There was no difference in SECI between patients with and without IEM (p = 0.91). SECI was also similar between patients with and without secondary peristalsis for IEM (p = 0.63) or normal motility (p = 0.80). No difference in SECI was seen between patients with and without MRS for IEM (p = 0.55) or normal motility (p = 0.88). SECI was significantly higher in male patients than female patients in IEM patients (p = 0.01). SECI significantly correlated with age in patients with normal motility (r = -0.31, p = 0.01). Aging may have a negative impact on SEC in patients with normal motility, while gender difference in SECI occurs in IEM patients. Neither secondary peristalsis nor MRS influences SECI.

Cardiorespiratory failure induced by inhalation of aerosolized fentanyl in anesthetized rats

Intravenous rapid injection of fentanyl causes respiratory depression (severe apneas), leading to sudden death, which constitutes the deadliest drug reaction among overdoses of synthetic opioids. Here we asked whether acute inhalation of overdose fentanyl would also result in similar respiratory failure and death. The anesthetized and spontaneously breathing rats with tracheal cannulation were exposed to aerosolized fentanyl at 100 mg/m3 (FNTH) or 30 mg/m3 (FNTL) for 10 min. Minute ventilation (VE), electromyography (EMG) of the internal and external intercostal muscles and thyroarytenoid muscles (EMGII, EMGEI, and EMGTA), heart rate and arterial blood pressure were recorded. During the exposure, FNTH and FNTL immediately triggered bradypnea (40 % reduction, p < 0.05) with TE prolonged and then gradually decreased VE by 40 % (P < 0.05) after a brief VE recovery. The initial TE prolongation (apneas) were characterized by the cessation of EMGEI activity with enhanced tonic discharges of EMGTA and EMGII. After termination of the exposure, the cardiorespiratory responses to FNTL returned to the baseline values 30 min later, while those to FNTH were greatly exacerbated (P < 0.05), leading to ventilatory and cardiac arrest occurred 16.4 ± 4.7 min and 19.3 ± 4.5 min respectively after the onset of FNTH. The ventilatory arrest was featured by cessation of both EMGEI and EMGII and augmentation of tonic EMGTA. Our results suggest that acute exposure to an overdose of fentanyl aerosol leads to death through initially inducing a brief central and upper airway obstructive apnea as well as chest wall rigidity followed by gradual severe hypoventilation, bradycardia and hypotension, and eventual cardiorespiratory arrest in anesthetized rats.

A Simple, Rapid, and Effective Method for Tumor Xenotransplantation Analysis in Transparent Zebrafish Embryos.

In vivo studies of tumor behavior are a staple of cancer research; however, the use of mice presents significant challenges in cost and time. Here, we present larval zebrafish as a transplant model that has numerous advantages over murine models, including ease of handling, low expense, and short experimental duration. Moreover, the absence of an adaptive immune system during larval stages obviates the need to generate and use immunodeficient strains. While established protocols for xenotransplantation in zebrafish embryos exist, we present here an improved method involving embryo staging for faster transfer, survival analysis, and the use of flow cytometry to assess disease burden. Embryos are staged to facilitate rapid cell injection into the yolk of the larvae and cell marking to monitor the consistency of the injected cell bolus. After injection, embryo survival analysis is assessed up to 7 days post injection (dpi). Finally, disease burden is also assessed by marking transferred cells with a fluorescent protein and analysis by flow cytometry. Flow cytometry is enabled by a standardized method of preparing cell suspensions from zebrafish embryos, which could also be used in establishing the primary culture of zebrafish cells. In summary, the procedure described here allows a more rapid assessment of the behavior of tumor cells in vivo with larger numbers of animals per study arm and in a more cost-effective manner.

Optimal dispatch strategy of battery energy storage system in utility-scale photovoltaic integrated grid under variability

The frequency response of a photovoltaic (PV) system integrated power grid is severely hampered due to inadequate inertial support. Integrating a battery energy storage system (BESS) can assist in maintaining frequency response by providing a rapid injection of active power into the grid. Nevertheless, instead of typical constant droop settings enabled in BESS, adopting variable PV power dependent operation of BESS can ensure frequency stability with reduced injection, especially in PV-integrated grids. From this viewpoint, this paper proposes a novel frequency control approach of BESS depending on the available PV power in the grid. A gradient descent-based optimization is utilized to evaluate the required maximum injection from the installed BESS to maintain frequency response under different PV generation values. This approach is then tested by modifying the BESS frequency controller to keep the active power dispatch from BESS within the calculated value under a given outage. The whole methodology is analyzed in a customized IEEE 39 bus New England System under different PV penetration and generation scenarios. The results indicate successful convergence to optimal dispatch levels for the BESS across all evaluated scenarios. As PV generation increases, the optimal BESS dispatch as a percentage of rated PV output declines gradually. However, at lower PV generation, this value rises rapidly and reaches the installed BESS capacity. Later, the applicability of the methodology is validated by comparing the simulated outputs with different test grid network and another support technique- Synchronous Condenser (SC). From the standpoint of frequency stability, the proposed technique can assist the grid planners in regulating BESS operations in a renewable integrated grid more effectively.

Power Quality Improvement in Hybrid Power System using STATCOM :

Meeting the escalating electricity demands posed by population growth and industrial expansion presents a significant challenge. Utilizing renewable energy sources like wind, biomass, and hydro co-generation has become imperative to satisfy energy requirements. In this proposed framework, a model featuring a grid-integrated wind energy generation system and nonlinear load is developed using MATLAB/Simulink. Integrating wind energy into the power grid impacts electricity quality, notably manifesting in voltage fluctuations, harmonics, flicker, and poor power factor at the source. The efficacy of a wind turbine and, consequently, electricity quality are assessed. To enhance power quality, the project advocates for the implementation of a STATCOM control strategy in grid-connected wind power systems. A bang-bang controller, based on hysteresis current control, is devised for STATCOM. Integrating STATCOM with the Point of Common Coupling (PCC) mitigates power quality issues. In this envisioned scheme, the FACTS device STATCOM is linked with battery power storage (BESS) at the PCC to alleviate power quality concerns. Incorporating Battery Energy Storage Systems aids in stabilizing the real power source during wind power fluctuations and facilitates the rapid injection of reactive power at the PCC. Keywords: Wind energy, Solar Energy, STATCOM, Electric grid, IGBT, PWM.) etc.

Sudden Death Induced by Rapid Intravenous Injection of Fentanyl in Conscious Rats

The sudden death induced by rapid intravenous (IVr) injection of overdose FNT in clinical settings is commonly observed in conscious humans and more often in the males than females. Our previous study has shown that IVr injection of FNT induces a long-lasting apnea associated with bradycardia and hypotension in anesthetized rats (Zhuang et al. 2023 EB). This study aimed to determine whether a lethal dose of FNT could cause sudden death with the mortality being higher in male rats than female ones and whether the FNT-induced respiratory disorder, especially ventilatory arrest, but not cardiac arrest, was the trigger of the death. The rat previously instrumented with ECG electrodes and jugular vein cannulation was placed in a restraint tube that was connected to a plethysmograph chamber to record cardiorespiratory activities. We found that FNT at doses &lt;2 mg/kg induced an immediate persistent apnea, lasting less than 1 min, associated with bradycardia. Following restoration of respiratory rhythm, the rats showed depressed VE and bradycardia for several hours and the cardiorespiratory variables recovered next day. A lethal dose of FNT at 3 mg/kg, compared to FNT at &lt;2 mg/kg, induced an even longer apnea (lasting &gt;1.5 min) accompanied with more severe bradycardia. This sustained apnea was usually interrupted by brief restoration of breathing, which was followed by ventilatory and cardiac arrest occurring at approximately 5 min and 10 min post injection respectively. Although the initial cardiorespiratory response to FNT appeared to be similar in both genders, the death rate was relatively higher in male rats than female ones. In conclusion, our study establishes an animal model of IVr injection of overdose FNT-induced sudden death occurring within minutes. The sudden death is the result of ventilatory, but not cardiac, arrest following a brief restoration of respiratory activity from a sustained apnea. Supported by NIH R01 grants HL163512 and DA059063. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Inhalation of Aerosolized Fentanyl Induces Respiratory Disorder and Sudden Death in Anesthetized Rats

In synthetic opioids, fentanyl (FNT) is the deadliest in clinical settings, resulting from respiratory disorder (RD) including ventilatory depression (dVE) and apnea. Rapid intravenous injection of FNT has been reported to cause immediately central and upper airway obstructive apnea that is mediated by vagal afferents in anesthetized rat (Zhuang J et al, 2012 and 2023). Here we asked whether acute inhalation of FNT also induced similar RD. EMGs of the internal and external intercostal muscles and thyroarytenoid muscles (EMGII, EMGEI, and EMGTA), minute ventilation (VE), heart rate and arterial blood pressure were recorded in anesthetized rats exposed to aerosolized FNT for 10 min. Immediately after exposure to FNT at 100 mg/m3, the rats showed apneas and remarkable prolongation of expiratory duration (TE) associated with hypotension and bradycardia. The apneas were characterized by cessation of EMGEI activity (central apnea) with enhanced tonic discharges of EMGTA (vocal closure, i.e., obstructive apnea) and EMGII (expiratory muscle constriction, i.e., chest wall rigidity). After a brief rebound at ~0.5 min exposure when the cardiorespiratory activities almost recovered to the baseline level, the rats presented gradual dVE by reduction of VT and fR, lasting for approximately 10 min. Apneas and ventilatory arrest subsequently occurred, leading to cardiac arrest a few minutes later. In contrast, FNT at 50 mg/m3 initially failed to significantly change VE, but subsequently developed gradual dVE (70% reduction) with significant TE prolongation, bradycardia and hypotension. These cardiorespiratory responses disappeared 30 min later. Our results suggest that acute exposure to a lethal dose of aerosolized FNT initially induces both central and upper airway obstructive apnea followed by dVE and ventilatory arrest, which is responsible for the sudden death in anesthetized rats. Supported by NIH R01 grants HL163512 and DA059063. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Manipulation of magnetic beads for actively capturing Vibrio parahaemolyticus and nucleic acid based on microfluidic system.

Rapid biological detection of pathogen micro-organisms has attracted much attention for practical biomedical applications. Despite the development in this field, it is still challenging to achieve simple and rapid biological detection using the microfluidic method. Herein, we propose a novel strategy of biological detection that combines precise detection control of the capillary microfluidic chip and versatile manipulation of magnetic beads. The microfluidic chip was fabricated via laser cutting, which utilized capillary pressure to realize rapid passive injection of liquid samples. Under an external magnetic field, the aptamer-modified magnetic beads were actuated to mix with Vibrio parahaemolyticus (V. parahaemolyticus) and its nucleic acid in the capillary microfluidic chip for rapid selective capture and detection, which could be achieved within 40 min. The experimental results demonstrated that V. parahaemolyticus could be captured using on-chip immunomagnetic beads with a high efficiency and significantly enhanced detection value. Due to these superior performances, the capillary microfluidic system, based on the manipulation of magnetic beads, demonstrated great potential for automatic biological detection.

Direct Implantation of Patient Brain Tumor Cells into Matching Locations in Mouse Brains for Patient-Derived Orthotopic Xenograft Model Development.

Background: Despite multimodality therapies, the prognosis of patients with malignant brain tumors remains extremely poor. One of the major obstacles that hinders development of effective therapies is the limited availability of clinically relevant and biologically accurate (CRBA) mouse models. Methods: We have developed a freehand surgical technique that allows for rapid and safe injection of fresh human brain tumor specimens directly into the matching locations (cerebrum, cerebellum, or brainstem) in the brains of SCID mice. Results: Using this technique, we successfully developed 188 PDOX models from 408 brain tumor patient samples (both high-and low-grade) with a success rate of 72.3% in high-grade glioma, 64.2% in medulloblastoma, 50% in ATRT, 33.8% in ependymoma, and 11.6% in low-grade gliomas. Detailed characterization confirmed their replication of the histopathological and genetic abnormalities of the original patient tumors. Conclusions: The protocol is easy to follow, without a sterotactic frame, in order to generate large cohorts of tumor-bearing mice to meet the needs of biological studies and preclinical drug testing.

Effect of Nonionic Iodinated Contrast Media on Blood Pressure during Contrast-enhanced Computed Tomography of Abdomen Examination: A Cross-sectional Study

ABSTRACT Introduction: Computed tomography (CT) scan has high sensitivity and specificity for numerous conditions. The images produced by a CT scanner can be enhanced using iodinated contrast media. Significant hemodynamic changes are seen with rapid intravenous contrast media injection. The average acceptable blood pressure (BP) value is 120/80 mmHg. Many studies have related hypertensive crises with high-osmolar contrast media, whereas its relation with low-osmolar contrast media is still unclear. This study aims to evaluate the effect of nonionic iodinated contrast media on BP during contrast-enhanced CT (CECT) of the abdomen. Materials and Methods: A cross-sectional study was conducted from April 2022 to August 2023. A total of 146 subjects (73 males and 73 females were included in the study). Statistical analysis of data was done using SPSS 23.0. A comparison of systolic BP and diastolic BP across the three periods was done using repeated measures of ANOVA. A between-group comparison was performed by unpaired t-test. The level of significance was set as 5%. All subjects underwent a CECT abdomen, including a plain, arterial, and venous phase. A bolus of 80 mL of Ultravist was administered. BP was measured before the contrast injection (baseline value), between the arterial and venous phases, and 3 min after the contrast injection. Results: Injection of nonionic contrast media caused a decrease in BP among subjects. The mean systolic BP readings before contrast injection in males and females were 127.5 ± 8 mmHg and 122.8 ± 8.4 mmHg, respectively. The mean diastolic BP before contrast injection was 79.2 ± 6.4 and 76 ± 6.4 mmHg among males and females, respectively. For systolic, these values decreased to 123 ± 10.3 mmHg in males and in females to 115 ± 14.6 mmHg when measured between arterial and venous phases. Similarly, for diastolic BP, the mean values recorded between the arterial-venous phase reduced to 76.7 ± 9.3 mmHg and 72.3 ± 10 mmHg, respectively. The BP readings, however, increased near baseline value when measured 3 min after the injection. The mean systolic BP measured 126.1 ± 8.5 mmHg and 124.9 ± 11.8 mmHg for males and females at 3 min after injection. Similarly, the mean diastolic BP values taken after 3 min of contrast injection were 78.3 ± 6.5 mmHg and 76.2 ± 7 mmHg in males and females, respectively, P &lt; 0.001. BP in both male and female groups was affected similarly. Conclusion: Bolus administration of 80 mL of Ultravist reduced BP. This reduction was short-term and got back to normal within a few minutes. The contrast media similarly affected both genders. The BP changes had no clinical significance.

Fabrication of NdFeB micromagnets based on vacuum negative pressure injection

Micromagnets integrated into microelectromechanical systems devices are widely used in the fields of micro-energy harvesters, micro-actuators, and speakers. A novel method for fabricating NdFeB micromagnets based on vacuum negative pressure injection is presented. The influence of array element shape, size, and injection channel on the surface magnetic field was studied by Maxwell finite element analysis. A circle array of 600 µm diameter and 150 µm spacing could generate a stronger magnetic field at the edge of the magnet array. Micron-sized magnetic powders with a diameter of 5 µm mixed with the SU8 T2010 photoresist were filled into the microcavity on a PDMS (polydimethylsiloxane) elastomer, which was prepared by the SU8 positive membrane. The PDMS elastomer was bonded to the glass substrate and degassed by a vacuum pump to form negative pressure for rapid injection and uniform filling. By selecting a suitable binder and optimizing the mixing ratio of the magnetic powder, a 165 µm thick micromagnet with homogeneous dispersion of magnetic powder particles was achieved, and the weight percentage of magnetic powder in the SU8 photoresist was 41.8%. The remanent magnetization of micromagnets was 42 emu/g, the coercivity was 6895 Oe, and the maximum surface magnetic field strength was 1.3 mT after magnetization in a 2 T uniform magnetic field. Finally, the micromagnet array was utilized in a cantilever beam micro-actuator, which could drive the cantilever beam and exhibit an excellent linearity.

Piped-slow-release calcium nitrate dosing: A new approach to in-situ sediment odor control in rural areas

Calcium nitrate addition is economically viable and highly efficient for the in-situ treatment of contaminated sediment and enhancement of surface water quality, particularly in rural areas. However, conventional nitrate addition technologies have disadvantages such as excessive nitrate release, sharp ammonium increase, and weakened sulfide oxidation efficiency owing to rapid nitrate injection into the sediment. To resolve these defects, we propose a piped-slow-release (PSR) calcium nitrate dosing method and investigate its treatment efficiency and underlying mechanisms. The results illustrated that PSR dosing had a longer half-life (t1/2 = 5.08 days) and a lower maximum apparent nitrate escape rate of 1.28 % than conventional nitrate injection and other dosing methods. In addition, the PSR managed the inorganic nitrogen release into the overlying water, and after the treatment, the nitrate, ammonium, and nitrite concentrations of 0 mg/L, 8.60 mg/L, and 0 mg/L on day 28 were close to those of the control group (0 mg/L, 8.76 mg/L, and 0 mg/L, respectively). Moreover, the PSR method maintained a moderate nitrate concentration of approximately 3000 mg/L in sediment interstitial water by its controlled-release design, thus greatly enhancing the sulfide oxidation efficiency by relieving the inhibitory effects of high nitrate concentrations, with 83.0 % sulfide being eradicated within 5 days. Sulfide-ferrous nitrate reduction (denitrification and dissimilatory nitrate reduction to ammonium) genera (e.g., Sulfurimonas, Thiobacillus, and Thioalkalispira) were successively enhanced and dominated the microbial community, and the related functional genes displayed high relative abundances. These results imply that the PSR dosing method for calcium nitrate, characterized by flexible operation, high efficiency, low cost, and controllable processes, is appropriate for remediating black-odorous sediment in rural areas.

A Rapid Continuous Flow Injection Analysis Method Development for Diphenhydramine Hydrochloride

Background: Diphenhydramine hydrochloride (DPH) is widely used as an antihistamine for treating various allergic conditions and symptoms. Traditional analytical methods for quantifying DPH often involve complex procedures and instrumentation. However, recent advancements in nanotechnology and analytical techniques offer opportunities for developing simpler and more efficient methods for DPH analysis. Method: This study presents a novel approach for quantifying DPH using continuous flow injection analysis (CFIA) combined with turbidimetric measurements. The precipitation reaction between DPH and 3,5-dinitro salicylic acid was utilized in an aqueous medium system. Various physical and chemical parameters were optimized, including the concentration of precipitating reagent, reaction medium (acids and salts), irradiation source intensity, volume of sample segment, and delay reaction coil. Results: Optimization of physical and chemical parameters revealed that a concentration of 15 m.mol/Liter for 3,5-dinitro salicylic acid, distilled water as the reaction medium, and an irradiation source intensity of 3.1 VDC produced optimal results. The linear dynamic range for DPH concentration was determined to be 0.01-20 m.mol/Liter. Comparison with the traditional UV-spectrophotometric method showed comparable results, indicating the reliability of the proposed CFIA method. Conclusion: The CFIA method presented in this study offers several advantages over traditional analytical methods for quantifying DPH in pharmaceutical formulations. It provides high sensitivity, speed, simplicity, and improved accuracy. The proposed approach has the potential for widespread application in pharmaceutical analysis, offering a cost-effective and easily manipulable solution for routine laboratory use. Overall, this study demonstrates a significant advancement in the measurement of DPH, which could simplify processes for pharmaceutical analysis and enhance industrial production levels.