81 research outputs found
Data-Based Semi-Automatic Hazard Identification for More Comprehensive Identification of Hazardous Scenarios
As chemical process plants have become more involved and complex, the likelihood of hazardous incidents has increased simultaneously. That is, the more complex a facilityâs systems, the more factors engineers must consider. This results in a higher likelihood of potential hazards being overlooked; thus, the possibility of incidents occurring increases.
Many companies and organizations are struggling to identify their weaknesses and reduce hazardous issues by developing hazard identification (HAZID) tools, particularly for large and complex processes. Even though a considerable number of companies merely pursue this objective to conform to government regulations, their efforts play a critical role in improving their reputations and financial profits. Therefore, the advancement of HAZID tools in the process industries has taken significant strides over the last 40 years.
Despite the substantial development of HAZID methods, traditional HAZID tools need further development because of their weaknesses in identifying possible hazards. In other words, it is evident that unintended incidents that occasionally occur in the chemical process industry require more enhanced HAZID methodologies. Therefore, this study attempts to ascertain the drawbacks of existing HAZID tools so that a new HAZID methodology, data-based semi-automatic hazard identification (DAHAZID), is proposed.
Considering potential HAZID methodologies, this study seeks to identify possible scenarios with a semi-automatic and systemic approach. Based on the two traditional HAZID tools, Hazard Operability study (HAZOP) and Failure Mode, Effects, and Criticality Analysis (FMECA), the DAHAZID method will minimize the limitations of each individual method. Additionally, rather than depending on the HAZID tools to achieve the connectivity of the process system, this study will consider connections with other new technologies in advance. Then, this method can be integrated with proper guidelines regarding process design and safety analysis. To examine its usefulness, the method will be applied to two case studies, and its outcome will be compared to the actual result, performed previously by a traditional HAZOP meeting.
Hopefully, this research can contribute to the further development of the process safety field in practice
Practical Inherently Safer Design Approaches During Early Process Design Stages Aiming for Sustainability
In traditional industrial process design approaches, techno-economic criteria have been the primary objectives in the early process design stages. Safety is often considered only in the later design stage (e.g., detailed engineering stage). Such a traditional approach is that most of the design degrees of freedom, including technology and configuration issues, have already been determined when considering safety. Modifying a process is costly or unreliable at later stages. To solve this issue, there have been numerous attempts to consider process safety during the early design stages in safety engineers and researchers. In particular, special attention to adopting inherently safer design (ISD) has been made because ISD is deemed the most cost-effective risk reduction strategy at early design stages. However, it is still challenging to adopt ISD for process engineers at the early design stages because of the lack of guidance and insufficient information on upcoming process facilities.
To address this challenge, this dissertation consists of three peer-reviewed journal papers [Articles #1 - #3]. With respect to the progress of inherently safer design (in particular, during the early design stage) over the last three decades, Article #1 selects 73 inherent safety assessment tools, which can be utilized during the early design stages, and categorized into three groups: hazard-based inherent safety assessment tools (H-ISATs) for 22 tools, risk-based inherent safety assessment tools (R-ISATs) for 33 tools, and cost-optimal inherent safety assessment tools (CO-ISATs) for 18 tools. The goal of this article is to enable process engineers to use all the available design degrees of freedom to mitigate risk early enough in the design process.
Article #2 analyzes 94 chemical process incidents investigated by the U.S. Chemical Safety and Hazard Investigation Board (CSB) reports. To analyze in a systematic approach, this article proposes 17 incident cause factors, 6 scenario factors, and 6 consequence factors to find out whether ISD would have helped to prevent these incidents.
Article #3 proposes hands-on predictive models of the flash point, the heat of combustion, lower flammability limit (LFL), and upper flammability limit (UFL). By incorporating the nonlinearity and transformation along with linearity of variables, this article constructed practical, reliable regression models thoroughly with readily available variablesâthe number of all atoms, molecular weights, and boiling points. The purpose is to enable a process engineer to quickly obtain hazardous properties of intended process materials
Recommended from our members
Physiological, proteomic, and whole-genome transcriptional responses of Nitrosomonas europaea to heavy metals (ZnÂČâș,CdÂČâș, CuÂČâș, and HgÂČâș) and cyanide : identification of heavy metals and cyanide stress response genes
Nitrosomonas europaea (ATCC19718) participates in the biological removal of nitrogen from wastewater by oxidizing ammonia to nitrite, the first step in nitrification. This bacterium is sensitive to heavy metals (ZnÂČâș, CdÂČâș, CuÂČâș, and HgÂČâș) and cyanide, compounds commonly encountered in wastewater treatment plants. Therefore, we characterized physiological and transcriptional responses of N. europaea cells exposed to these inhibitors in batch reactors to identify stress-induced genes. N. europaea exposed to 3.4 uM ZnClâ showed about 61% inhibition in nitrification within 30 minutes. In microarrays of N. europaea exposed to 3.4 uM ZnClâ for 60 minutes, 27 genes were observed to be up regulated more than 2-fold, of the total of 2460 genes, while 30 genes were seen to be down regulated. Up-regulated genes included mercury resistance genes (merTPCAD), inorganic ion transport genes, oxidative stress genes, toxin-antitoxin genes (TA). merTPCAD was the highest up regulated operon (46-fold). Down-
regulated genes included RubisCO (cbbO), biosynthesis (mrsA), and amino acid transporters. N. europaea exposed to 1 uM CdClâ, 6 uM HgClâ, or 8 uM CuClâ showed about 90% inhibition in nitrification within 30 minutes. In microarrays of N. europaea exposed to 1 uM CdClâ for 60 minutes, 66 genes were up regulated while 50 genes were down-regulated. merTPCADE showed the highest up regulation (277-fold) under cadmium stress. Interestingly, merA also showed 250-fold up regulation in N. europaea cells exposed to 6 uM HgClâ. Therefore, merTPCADE appear to be common stress response genes to zinc, cadmium, and mercury exposure. N. europaea cells were very sensitive to low concentrations of cyanide; nitrification decreased about 50% in 30 minutes after exposure to 1 uM NaCN. In microarrays of N. europaea exposed to 1 uM NaCN for 60 minutes, 35 genes showed up regulation while 29 genes showed down regulation. A gene cluster that included moeZ (NE2353), encoding a rhodanese homologue, thought to be involved in detoxification of cyanide, showed the highest up regulation (7-fold). The down-regulated genes included genes encoding proteins involved in the sulfate reduction pathway, signal transduction mechanism, carbohydrate transport, energy production, and coenzyme metabolism
Does a HAZOP reveal to us all the hazards we need to know, or are we overlooking serious threats?
PresentationThe HAZOP process as part of a PHA has been well established and in LinkedIn groups discussions have been on the best supporting software and best practices; the latter, e.g., on different opinions whether a checklist and pre-population is desirable. Of course, all are apprehensive to missing a significant scenario. On the other hand, required time and effort is also a concern. That there is good reason for being concerned about hazard identification completeness appears from various studies over the years, e.g., in which in hindsight after an incident is analyzed whether the scenario had been predicted. In those studies figures of only half of the important scenarios identified are common. Over the years several efforts have been published of attempts to semi-automate the process. Intelligent/smart P&ID is a jump forward. A recent report on automated HAZOP from a highly experienced engineer who can look back on many years of using it, shows good success. More is in the pipeline. Yet, the experience, competence, spirit and ingenuity of a HAZOP team in brainstorming sessions remain needed to see and weigh the risks, although it can be doubtful that, as some assert, it is the single source. The present study comprehends a relatively modest attempt with means that are on every laptop to support a HAZOP study, given the availability of an intelligent P&ID. This Data-based semi- Automatic HAZard IDentification (DAHAZID), seeks to identify possible scenarios with a semi-automated system applying both HAZOP and FMECA. The new method will minimize the limitations of each method. This will occur by means of a thorough systematic preparation before the tools are applied. Rather than depending on reading drawings to obtain connectivity information of process system equipment elements, this research is generating and presenting in prepopulated work sheets linked components together with all required information and space to note HAZID results. Next, this method can be integrated with proper guidelines regarding process safer design and hazard analysis. To examine its usefulness, the method has been applied to a case study
Development of a highly sensitive real-time one step RT-PCR combined complementary locked primer technology and conjugated minor groove binder probe
<p>Abstract</p> <p>Background</p> <p>Enterovirus (EV) infections are commonly associated with encephalitis and meningitis. Detection of enteroviral RNA in clinical specimens has been demonstrated to improve the management of patients, by ruling out other causes of disease.</p> <p>Method</p> <p>To develop a sensitive and reliable assay for routine laboratory diagnosis, we developed a real-time one step reverse transcription polymerase chain reaction (RT-PCR) assay with minor groove binder probes and primers modified with complementary locked primer technology (TMC-PCR). We checked the sensitivity of the developed assay by comparing it to a previously published TaqMan probe real-time one-step RT-PCR (TTN-PCR) procedure using enteroviral isolates, Enterovirus Proficiency panels from Quality Control on Molecular Diagnostics (QCMD-2007), and clinical specimens from patients with suspected EV infections.</p> <p>Results</p> <p>One hundred clinical specimens from 158 suspected viral meningitis cases were determined to be positive by the TMC-PCR assay (63.29%), whereas only 60 were found to be positive by the TTN-PCR assay (37.97%). The positive and negative agreements between the TMC-PCR and TTN-PCR assays were 100% and 59.2%, respectively.</p> <p>Conclusion</p> <p>This data suggest that the TMC-PCR assay may be suitable for routine diagnostic screening from patient suspected EV infection.</p
Process hazard analysis, hazard identification and scenario definition: are the conventional tools sufficient, or should and can we do much better?
Hazard identification is the first and most crucial step in any risk assessment. Since the late 1960s it has been done in a systematic manner using hazard and operability studies (HAZOP) and failure mode and effect analysis (FMEA). In the area of process safety these methods have been successful in that they have gained global recognition. There still remain numerous and significant challenges when using these methodologies. These relate to the quality of human imagination in eliciting failure events and subsequent causal pathways, the breadth and depth of outcomes, application across operational modes, the repetitive nature of the methods and the substantial effort expended in performing this important step within risk management practice. The present article summarizes the attempts and actual successes that have been made over the last 30 years to deal with many of these challenges. It analyzes what should be done in the case of a full systems approach and describes promising developments in that direction. It shows two examples of how applying experience and historical data with Bayesian network, HAZOP and FMEA can help in addressing issues in operational risk management
Naturally occurring radioactive materials (NORM) in the groundwater of two islands with various geologic settings in South Korea
Since 2007, Naturally Occurring Radioactive Materials (NORM) such as uranium-238 and radon-222 etc. in groundwater from the Community Water-supply Systems (CWS) in two islands have been studied in South Korea. In 71 samples from Ganghwa (G) Island, the maximum value of uranium-238 concentration is 72.21 ÎŒg/L. 3 CWSs (4.2%) exceeded the Maximum Contaminant Level (MCL) of 30 ÎŒg/L for uranium-238. The maximum value of radon-222 activity is 614 Bq/L. 28 CWSs (39.4 %) did not meet the United States Environment Protection Agency (US EPA) proposed Alternative Maximum Contaminant Level (AMCL) of 148 Bq/L for radon-222. At all CWS that did not meet the US EPAâs MCL or AMCL, some appropriate actions were taken such as water treatment, alternative well development, mixing water of different origins, and so forth. In the 52 CWSs of Jeju (J) Island, the maximum value of uranium-238 and radon-222 concentrations are 1.37 ÎŒg/L and 94.83 Bq/L, respectively. All values for uranium-238, gross alpha, and radon-222 meet MCL and proposed AMCL of US EPA drinking water standard. The two islands have different geological settings that are believed to be the causes of the big differences in the NORM levels. Geologically an old island has much higher NORM values than a young island formed in the Quaternary Period due to hydrogeological factors such as recharge and infiltration rates of precipitation. The residence times in the aquifers for water-rock (mineral) interactions are very different from each other.</p
Biobanking for glomerular diseases: a study design and protocol for KOrea Renal biobank NEtwoRk System TOward NExt-generation analysis (KORNERSTONE)
Abstract
Backgrounds
Glomerular diseases, a set of debilitating and complex disease entities, are related to mortality and morbidity. To gain insight into pathophysiology and novel treatment targets of glomerular disease, various types of biospecimens linked to deep clinical phenotyping including clinical information, digital pathology, and well-defined outcomes are required. We provide the rationale and design of the KOrea Renal biobank NEtwoRk System TOward Next-generation analysis (KORNERSTONE).
Methods
The KORNERSTONE, which has been initiated by Korea Centres for Disease Control and Prevention, is designed as a multi-centre, prospective cohort study and biobank for glomerular diseases. Clinical data, questionnaires will be collected at the time of kidney biopsy and subsequently every 1 year after kidney biopsy. All of the clinical data will be extracted from the electrical health record and automatically uploaded to the web-based database. High-quality digital pathologies are obtained and connected in the database. Various types of biospecimens are collected at baseline and during follow-up: serum, urine, buffy coat, stool, glomerular complementary DNA (cDNA), tubulointerstitial cDNA. All data and biospecimens are processed and stored in a standardised manner. The primary outcomes are mortality and end-stage renal disease. The secondary outcomes will be deterioration renal function, remission of proteinuria, cardiovascular events and quality of life.
Discussion
Ethical approval has been obtained from the institutional review board of each participating centre and ethics oversight committee. The KORNERSTONE is designed to deliver pioneer insights into glomerular diseases. The study design allows comprehensive, integrated and high-quality data collection on baseline laboratory findings, clinical outcomes including administrative data and digital pathologic images. This may provide various biospecimens and information to many researchers, establish the rationale for future more individualised treatment strategies for glomerular diseases.
Trial registration
NCT03929887
Aspirination of α-Aminoalcohol (Sarpogrelate M1)
Aspirination of α-aminoalcohol (sarpogrelate M1) has been performed under various general esterification conditions. In most cases, the desired aspirinate ester was obtained at a low yield with unexpected byproducts, the formation of which was mostly derived from the chemical properties of the tertiary α-amino group. After systematic analysis of those methods, the aspirinated sarpogrelate M1 was prepared using a two-step approach combining salicylate ester formation and acetylation
- âŠ