Coordination Clusters Research Articles

Reductive amination of phenol over Pd-based catalysts: elucidating the role of the support and metal nanoparticle size

The Pd-catalyzed reductive amination of phenol is sensitive to the support's nature, and to the atoms' coordination in palladium clusters.

Heterogeneous Aggregation and Control Modeling for Electric Vehicles With Random Charging Behaviors

Electric vehicles (EVs) with both power consumption and energy storage are important load resources involved in the adjustment of supply and demand. The aggregation and control of a large number of EVs is a way to make the energy structure upgrade. This paper plans to explore the cluster response mechanism, group effect and coordination ability of distributed EVs in the regional power grid on the basis of solving the following problems. Firstly, the EV cluster presents heterogeneous characteristics due to differences of physical parameters. Secondly, EVs participating in the aggregation dynamically change in real time because of the stochastic charging behaviors. In this paper, a heterogeneous aggregation model for EVs with random charging behaviors is proposed based on the changing relation of charging power to remaining electric quantity. And a variable sliding mode control model is constructed to address the randomness of the charging process and realize stable responses in a short-time scale. Besides, the battery module and the user strategy are proposed to coordinate with the heterogeneous cluster to improve the adjustment capacity and flexibility. Finally, A clean energy output tracking simulation is provided to verify the effectiveness of the heterogeneous aggregation and control model.

A tetracobalt(II) cluster with a two vertex truncated dicubane topology endogenously supported by carboxylate-based (2-pyridyl)methylamine ligands: magneto-structural and DFT studies.

A reaction between CoCl2 and L3-(CO2-)2 (2 : 1 stoichiometry) in CH3OH affords a discrete complex [CoII4-{L3-(CO2-)2}2(μ3-OCH3)2(CH3OH)2(H2O)2Cl2] (1) [L3-(CO2-)2 = 3-[N-{2-(pyridin-2-yl)methyl}amino]-bis(propionate)]. The structure of 1 reveals two terminal mononuclear CoII{L3-(CO2-)2}Cl units connected by a dimeric CoII2(μ3-OCH3)2(CH3OH)2(H2O) unit present in the centre through two methoxo (μ3-OCH3)- and two carboxylate (μ-1,1-OCO-) bridges affording a tetranuclear coordination cluster of Co(II) with a defective dicubane topology. In 1, Co1 (terminal) has distorted octahedral CoIIN2O3Cl and the central Co2 has CoIIO6 coordination. Such coordination arrangements afford the observed topology. Variable-temperature magnetic studies reveal anti-ferromagnetic coupling in 1. Three magnetic exchange interactions (one anti-ferromagnetic and two ferromagnetic: J1 = +3.3 cm-1 (Co⋯Co 3.176 Å; μ-1,1-OCO- and μ3-OCH3 bridges), J2 = -2.5 cm-1 (Co⋯Co 3.228 Å; μ-1-OCO- and μ3-OCH3 bridges) and J3 = +10.6 cm-1 (Co⋯Co 3.084 Å; two μ3-OCH3 bridges)) have been identified, with the inclusion of the orbital reduction parameter (α = Aκ = 1.38), spin-orbit coupling (λ = -158 cm-1) and axial distortion (energy gap Δ = -975 cm-1 between singlet and doublet levels), rationalized by density functional theory (DFT) calculations.

Hierarchical Cluster Coordination Control Strategy for Large-scale Wind Power Based on Model Predictive Control and Improved Multi-time-scale Active Power Dispatching

Hierarchical Cluster Coordination Control Strategy for Large-scale Wind Power Based on Model Predictive Control and Improved Multi-time-scale Active Power Dispatching

Implementation of an evidence-based tobacco control intervention for school teachers in India: Evaluating the effects of a capacity-building strategy.

Tobacco-Free Teachers, Tobacco-Free Society (TFT-TFS) is an evidence-based intervention that promotes tobacco use cessation among teachers and tobacco control policies among schools in India. This study tested an implementation model to build Bihar Department of Education (DOE) capacity to support and deliver TFT-TFS within schools, leveraging DOE training infrastructure. We used a training-of-trainers (TOT) "cascade" implementation strategy to embed the TFT-TFS program into the Bihar DOE infrastructure. We trained 46 Cluster Coordinators to train and support Headmasters to implement TFT-TFS in their schools over one academic year. We selected three school districts, representing approximately 46 clusters and 219 schools. We used the RE-AIM framework to assess program adoption (Headmaster participation in at least one of six TFT-TFS trainings), implementation (of four core program components), and reach (teachers' participation in three or more group discussions). Using a non-inferiority design, we hypothesized that program adoption, implementation, and reach would not be inferior to the high standards demonstrated when TFT-TFS was originally tested in the Bihar School Teachers Study. We used self-reported checklists to measure outcomes and SPSS Version 25 to analyze data. For adoption, 94% of Headmasters attended the first training, although participation declined by the sixth training. Among the 112 schools out of 219 with complete Headmaster checklist data, all met our minimum criteria for implementing TFT-TFS. Over 99% of schools posted a school tobacco control policy and distributed quit booklets. However, only 69% of schools met our criteria for program reach. This study outlines the processes for taking a tobacco control intervention to scale and implementing it through the Bihar DOE infrastructure. These findings provide a foundation for other Indian states and low- and middle-income countries to implement tobacco control and other health programs for schoolteachers. NCT05346991. Each year in India, more than 1.2 million people die from tobacco-related causes, and India has the world's highest oral cancer burden. The world needs more evidence on how to bring cost-effective tobacco control interventions to scale, especially in low- and middle-income countries (LMICs). To address this gap, from 2017 to 2021, we examined the process of scaling up Tobacco-Free Teachers, Tobacco-Free Society (TFT-TFS), an evidence-based intervention promoting tobacco use cessation among teachers and tobacco control policies in schools. Our study tested an implementation model aimed at building the Bihar State Department of Education (DOE) capacity to support and deliver TFT-TFS. We used a training-of-trainers model to embed TFT-TFS into Bihar DOE infrastructure, training 46 Cluster Coordinators to in turn train and support Headmasters to implement TFT-TFS over one academic year. We hypothesized that program adoption, implementation, and reach would not be inferior to the high standards demonstrated when we originally tested TFT-TFS through the Bihar School Teachers Study (2013-2017). For adoption, 94% of Headmasters attended the first training, although participation declined by the sixth training. Of 112 schools (out of 219 with complete Headmaster checklist data), all met our minimum criteria for implementing TFT-TFS. Over 99% of schools posted a school tobacco control policy and distributed quit booklets. However, only 69% of schools met our criteria for program reach. Study findings offer other Indian states and LMICs lessons to implement tobacco control and other health programs for schoolteachers within educational systems.

The Anion-Dominated Dynamic Coordination Field in the Electrolytes for High-Performance Lithium Metal Batteries

Electrolyte plays a dominant role in solving the various challenges of Li-metal batteries (LMBs). The complex competition coordination and diversity of the anion coordination clusters in electrolytes are still unclear. In this paper, an anion-dominated dynamic coordination field (ADCF) theory is proposed to reasonably explain the coordination behavior in the high-concentration, localized high-concentration, and weak-ionization localized high-concentration electrolytes, which is based on specific characterizations and theoretical calculations. The novel model selects the anions as the center of the whole molecular groups/clusters, while the Li+ acts as the counterion or carrier, which can promote the dynamic and elastic movement of the whole cluster. The specific coordination clusters could remarkably enhance the interaction between TFSI− and Li+, and make the counterion composition of Li+ increase. The confinement effect of the coordination field provides a difficult ionization atmosphere for the Li+, and enables clusters to preferentially adsorb on the Li surface, and construct a specific solid electrolyte interphase (SEI). Furthermore, the electrode/electrolyte interface kinetics and the growth of lithium dendrites are systematically investigated. These new viewpoints of coordination behavior provide inclusive strategies in the electrolyte design, and promote further research of the charge transfer or solution behavior.

A Novel CSINR Technique for Accurate and Precise GPS Communication by Geographical Centric Self-learning Nodes

Since its introduction, the Global Positioning System (GPS) is finding many countless, useful, and emergency applications, focused mainly on track. As the technology is advancing day by day and the best feature of GPS, which does not, relies on mobile signal to work, making it a feasible feature to incorporate into other devices as functionalities. By adopting GPS to a system, accurate mapping and geographical labeling can be obtained. GPS works better with the coordination of nodes and requires centralized monitoring and a reporting system. As it is a known fact that a demerit follows merit anywhere else, In GPS also, the major attention is required to make the nodes to success in mapping the intermediate space between agent node used for reporting and the remaining nodes of a cluster, where satellite and node coordination can be possible integer ambiguity technique. Many researchers have proposed solutions to the aforementioned problem; unfortunately still today the proposed methods are weaker in achieving lesser time delay of Total Electron Content (TEC). The proposed Centric Self-Learning Interconnected Nodes Reading (CSINR) technique is novel in terms addressing the intermediate nodes failing to label the inter-connected object spaces between reporting agents and nodes using integer ambiguity technique for node co-ordination and using a dedicated GPS prediction-based clock system, which predicts precise and accurate mapping between interconnected nodes. Based on the information shared between among the network managers a separate pseudo-connected network will be formed and further this network will be considered an interconnected nodes network. From the information calculated from temporal factors and clock offset the separate pseudo network is extracted by using the proposed CSINR technique. Add-on self-improvement is introduced to the proposed method by a self--learning feature to an individual join extract the principal rate of partisan neighbouring join to sustain accuracy in order consistent basis. An evaluation ratio of 97.43%, sensitivity of node occurrence is resulted as 92.78% and accuracy of 97.43% and 97.12% is achieved among a cluster of 32and 64 nodes respectively.

Preparation and application of bimetallic coordination cluster Cu7Mn2 for dispersive solid phase extraction of polycyclic aromatic hydrocarbons in lettuce

In this study, bimetallic coordination cluster Cu7Mn2 was synthesized by solvent thermal method and based on the features of large specific surface area, rich adsorption sites, the material was applied for the dispersive solid-phase extraction of pyrene, fluoranthene, phenanthrene and fluorene in lettuce followed by high performance liquid chromatography analysis. The sythesized Cu7Mn2 cluster was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, hydrophobicity and nitrogen adsorption-desorption experiments. The adsorption kinetics and adsorption isotherms were carrued out. Then, the adsorption mechanism was speculated to be the coexistence of π − π stacking, hydrophobic interaction and N−H···π interaction. The adsorption experimental results indicated that Cu7Mn2 cluster had better adsorption properties for pyrene, fluoranthene, phenanthrene, fluorene than Cu cluster and Mn cluster. The extraction conditions such as the kind and volume of desorption solvent, the adsorption and desorption time, the sample volume and salinity were investigated. Under the optimal conditions, a DSPE-HPLC method was developed for the determination of pyrene, fluoranthene, phenanthrene and fluorene in lettuce. The linearities were 0.5 − 1000 μg/kg for phenanthrene, fluorene and 3−1000 μg/kg for pyrene, fluoranthene (R2 >0.99), respectively. The limits of detection (LODs, S/N = 3) and the limits of quantification (LOQs, S/N = 10) were in the ranges of 0.12−0.81 μg/kg and 0.40 − 2.7 μg/kg, respectively. The intra- and inter-day precisions (RSDs) were less than 2.9% and 4.0%, respectively, and the recoveries were in the range of 94.9% − 101.1%. The established DSPE-HPLC method has been proven to be accurate for the analysis of four polycyclic aromatic hydrocarbons in lettuce samples.

Ag(II) as Spin Super-Polarizer in Molecular Spin Clusters.

Using quantum mechanical calculations, we examine magnetic (super)exchange interactions in hypothetical, chemically reasonable molecular coordination clusters containing fluoride-bridged late transition metals or selected lanthanides, as well as Ag(II). By referencing to analogous species comprising closed-shell Cd(II), we provide theoretical evidence that the presence of Ag(II) may modify the magnetic properties of such systems (including metal-metal superexchange) to a surprising degree, specifically both coupling sign and strength may markedly change. Remarkably, this happens in spite of the fact that the fluoride ligand is the least susceptible to spin polarization among all monoatomic ligands known in chemistry. In an extreme case of an oxo-bridged Ni(II)2 complex, the presence of Ag(II) leads to a nearly 17-fold increase of magnetic superexchange and switching from antiferro (AFM)- to ferromagnetic (FM) coupling. Ag(II)─with one hole in its d shell that may be shared with or transferred to ligands─effectively acts as spin super-polarizer, and this feature could be exploited in spintronics and diverse molecular devices.

Enhanced photocatalytic hydrogen evolution with a Mixed-Valence iron Metal-Organic framework

Fe-oxo cluster-based metal–organic frameworks (MOFs) offer a tunable platform for visible-light-driven catalysis, yet the unmatched energy level and the ease of charge recombination strongly hinder their application in photocatalytic H2 generation. In this work, we report an Fe(II/III) mixed-valence catalyst derived from the transition of an Fe(II)2N2O10 cluster-based MOF in water through a solvent displacement pathway. Both electronic band structure and charge transfer dynamics are effectively optimized via heteroatom coordination and valence mixing in the iron clusters. 25 times the visible-light-induced H2 yield of pristine FeMOF was obtained by Fe(II/III) MOF with platinum as cocatalyst. The Fe MOF catalyst also shows significantly superior performance in comparison with the well-known oxide catalyst α-Fe2O3 and the commonly investigated MOF catalyst NH2-UiO-66. This work provides a direction for the structural engineering of Fe-MOFs for photocatalysts.

Sex Differences in Fecal Microbiome Composition and Function of Dromedary Camels in Saudi Arabia.

The gastrointestinal microbiome plays a significant role in diet digestion and the energy production of its host. Several factors that affect the gastrointestinal microbiota composition were studied in camels. Yet, the impact of sex on the gastrointestinal bacteriome of camels remains unexplored to date. In this perspective, the fecal microbiome community composition from dromedary camels was determined in 10 male and 10 female samples using the 16S rRNA amplicon, in order to estimate if this was influenced by sex. The core microbiome in females contained 284 bacterial OTUs and one archaeal OUT, whereas in males, it contained 279 bacterial OTUs and one archaeal OTU. In females, Bacteroidetes and Spirochaetes were significantly more abundant than in male camels, whereas Lentisphaerae and Euryarchaeota were significantly abundant in males. According to Principal Coordinate Analysis and UPGMA clustering, grouping with respect to sex was observed. The functional prediction results showed differences such as energy production and conversion, and that the cell wall/membrane/envelope were enriched in female camels. The fecal microbiome of male camels was rich in amino acid, lipid transport and metabolism.

Synthesis, Crystal Structures, and Magnetic Properties of Two FeIII–DyIII Coordination Clusters with N,N,N',N'-Tetrakis(2-hydroxyethyl)ethylenediamine (edteH4) as Ligand

Synthesis, Crystal Structures, and Magnetic Properties of Two FeIII–DyIII Coordination Clusters with N,N,N',N'-Tetrakis(2-hydroxyethyl)ethylenediamine (edteH4) as Ligand

An advancement in energy efficient clustering algorithm using cluster coordinator-based CH election mechanism (CCCH)

A mobile ad hoc network comprises several nodes, and each node can send messages (data) on demand without any established infrastructure. Mobile nodes dynamically enter and exit the network often, resulting in unstable network topology in MANET. As a result, maintaining a stable network becomes a challenging task. Path preservation, battery life, safety, dependability, and unexpected connection characteristics are the major issues in MANET. The network's quality of service (QoS) would be impaired as a result (QoS). The routing protocol is vital for MANETs' pathway detection and maintenance. The multicast routing technology may significantly increase the reliability of the MANET network. Clustering methods, which enable the structuring of networks into groups known as entities or clusters, are invariably employed to address such problems. This paper presents a cluster coordinator-based CH election mechanism (CCCH). The cluster coordinator (CC) is in charge of carrying out the entire operation and is the most important entity in this scenario. The cluster coordinator (CC), cluster head (CH), and cluster members (CM) are the three entities that make up the proposed model. Next to the cluster coordinator, the Cluster Head (CH) is the important serving node in each cluster. Each node in a cluster has a unique value for factors such as node mobility, degree, identity, and energy, among others. With the least amount of time and energy use, the combined proposed architecture successfully constructed reliable routing. A comparison study is done with the existing Optimal Route Selection for Mobile Ad Hoc Networks (ORSMAN) [13] and ticket ID cluster manager protocol (TID-CMGR) [14] to assess the performance of the proposed CCCH. The comparison result proves that the proposed algorithms' performance is far better than the others in all evaluation metrics, such as energy consumption, packet delivery ratio (PDR), and the number of CH changes.

Field‐Induced SMM Behaviour of Tetranuclear Coordination Clusters with a Cubane [Ni4O4] Core

AbstractTwo tetranuclear Ni(II) complexes: [Ni4(HL1)4] ⋅ H2O (1) and [Ni4(HL2)4] ⋅ 1.5 dmf (2) where dmf=dimethylformamide, H3L1=4‐(tert‐butyl)‐2‐(((2‐hydroxy‐5‐nitrophenyl)imino)methyl)‐6‐(hydroxymethyl)phenol and H3L2=4‐(tert‐butyl)‐2‐(hydroxymethyl)‐6‐(((2‐hydroxyphenyl)‐imino)methyl)phenol, have been prepared and characterized by single crystal X‐Ray diffraction, elemental analysis and FT‐IR spectroscopy. The solid‐state structures reveal the formation of highly symmetric and asymmetric [Ni4O4] cubane cores in complexes 1 and 2, respectively. Extensive magnetic studies show that both complexes present ferromagnetic exchange interactions between the Ni(II) ions within the cubane core with g=2.113(3), J1=−7.89(8) cm−1, J2=13.3(1) cm−1 and |D|=11.3(4) cm−1 (for 1) and g=2.206(4), J1=1.0(1) cm−1, J2=7.8(1) cm−1 and |D|=8.7(2) cm−1 (for 2). The large anisotropy, high ground spin state (arising from the ferromagnetic coupling) and the good isolation of the clusters provided by the Schiff base ligands, give rise to the first examples of field‐induced single‐molecule magnets (FI−SMM) in Ni4O4 clusters and to the highest energy barrier reported to date in a Ni4O4 cluster.

The Intriguing mitoNEET: Functional and Spectroscopic Properties of a Unique [2Fe-2S] Cluster Coordination Geometry.

Despite the number of cellular and pathological mitoNEET-related processes, very few details are known about the mechanism of action of the protein. The recently discovered existence of a link between NEET proteins and cancer pave the way to consider mitoNEET and its Fe-S clusters as suitable targets to inhibit cancer cell proliferation. Here, we will review the variety of spectroscopic techniques that have been applied to study mitoNEET in an attempt to explain the drastic difference in clusters stability and reactivity observed for the two redox states, and to elucidate the cellular function of the protein. In particular, the extensive NMR assignment and the characterization of first coordination sphere provide a molecular fingerprint helpful to assist the design of drugs able to impair cellular processes or to directly participate in redox reactions or protein-protein recognition mechanisms.

Unusual oxygen…oxygen dichalcogen bond in an oxo-centered trinclear iron coordination cluster

An oxo-centred, carboxylate bridged trinuclear iron(III) coordination cluster, [Fe3O(2-furoate)6(H2O)1.8(NCS)1.2].H2O (1) was prepared by the reaction of FeCl2·4H2O with 2- Furoic acid, and KSCN in mixed solvents (CH3CN: CH2Cl2). The structure of the compound was identified by FTIR, elemental analysis and Single X-ray Crystallography. The trinuclear iron complex is planar in structure with weak intermolecular interactions i.e. O…O, C-H…π or O…π or π…π, can be seen in the structure to form more stable 3D supramolecular architecture with cavity-channels (O…O distance between furoic oxygen = 4.214 Å). Theoretical investigation has been executed and confirmed about the oxygen…oxygen dichalcogen bond. The energy of unconventional O···O chalcogen bond calculated as 0.6 kcal/mole. Further, QTAIM and NCI methods also expose non-covalent interactions. The QTAIM also confirms about the presence of weaker C-H···S hydrogen bonds of ρ oscillating around 0.005 au. The studied iron complex is a rare example of a system stabilized by O ···O dichalcogen bonding interactions.

Silver alkynyl coordination chains and clusters assembled with sulfonates

The metal cluster can be controlled by adjusting the size of the anionic templates and by using different peripheral organic ligands. In this paper, we employ RCCAg (R = 4-tBu-Ph, Ph, tBu), CF3SO3Ag, NH4X (X = Br, VO3) acting as starting materials to obtain four silver ethynide complexes incorporating the sulfonate ligands, namely, [Ag3(4-tBu-PhCC)2(CF3SO3)]n (1), {[Br@Ag15(PhCC)10(CF3SO3)4][Ag4(PhCC)4][Br@Ag15(PhCC)10(CF3SO3)4]}n (2), [Br@Ag15(tBuCC)10(CF3SO3)4]n (3) and [V2O7@Ag24(tBuCC)14(CF3SO3)6] (4). Single-crystal X-ray analysis revealed that complexes 1–3 display different coordination chain structures, while 4 contain high-nuclearity silver(I) composite clusters enclosing a [V2O7]4− template ion, that are supported by CF3SO3- ligands.

High-Voltage Symmetric Nonaqueous Redox Flow Battery Based on Modularly Tunable [Ru2M(μ3-O)(CH3CO2)6(py)3] (M = Ru, Mn, Co, Ni, Zn) Cluster Compounds with Multielectron Storage Capability

Redox flow batteries (RFBs) provide an attractive solution for large-scale energy buffering and storage. This report describes the development of nonaqueous RFBs based on trimetallic coordination cluster compounds: [Ru2M(μ3-O)(CH3CO2)6(py)3] (M = Ru, Mn, Co, Ni, Zn). The all-ruthenium complex exhibited stable battery cycles in anolyte–catholyte symmetric operation, with rarely observed multielectron storage in a single molecule. Moreover, the complex holds modularly tunable synthetic handles for systematic improvements in solubility and redox potentials. An optimized battery stack containing [Ru3(μ3-O)(CH3CO2)6(py)3]+ anolyte and [Ru2Co(μ3-O)(CH3CO2)6(py)3] catholyte yielded stable cycles with a discharge voltage of 2.4 V, comparable to the state-of-the-art nonaqueous RFBs. Explanation for the exceptional stability of the charged states and prediction of systematic tunability of the redox potentials of the cluster compounds were assisted by DFT calculations.

Exploring potential drivers of innovation-related activities in Poland: evidence from Polish business clusters

Research background: Innovations are introduced by competitive companies. One of the most common methods, increasingly used by companies, is organizing clusters or cluster initiatives operating within a specialized sector, competing with each other, exploiting the potential of cooperation and its impact on creating new business ideas. However, these efforts could be unviable due to the lack of an effective leader of the group. One should underline a crucial role of the leader in such an organized network, since the leader makes improvements and takes initiatives for all the network and its partners. These concepts prompt us to undertake the research on the role of clusters? characteristics on enhancing willingness to innovate in general. This study aims to point out the main characteristics of clusters and to investigate their impact on companies? innovativeness. The main problem to address is the magnitude of specific effects that might boost introducing new solutions in firms? networks. Purpose of the article: The purpose of this study is to investigate the impact of factors describing cluster environment (characteristics like cooperation within clusters and beyond them, incentives of a leader, and localization factors) that might affect the innovativeness of companies. Methods: The authors collected data using questionnaire. This type of primary source enables the authors to construct a model consisting of latent variables such as incentives of coordinator of cluster or cluster initiative, cooperation of firms with local authorities, cooperation between entrepreneurs, or localization. The results are subject to the Structural Equation Modelling (SEM) analysis. Findings & value added: The conducted analysis leads to several findings. Firstly, incentives provided by the cluster coordinator enable companies to increase the willingness to introduce innovations in general. Secondly, however, the influence of other cluster characteristics on the propensity to innovate for firms functioning within specific Polish business clusters is scant. These findings point to the fact that actions leading to assign the official coordinator of a cluster need to be done, as it should result in better flow of knowledge, more symmetric information among companies within cluster, and more productive and innovative way of functioning firms in general. Regarding innovation clusters (and regional innovation systems), these actions need to be supported by forming policy on regional level, because effective clusters would induce more competitive regional economy in long-term scenario.

Prevalence, types, patterns and risk factors associated with drugs and substances of use and abuse: A cross-sectional study of selected counties in Kenya

The increasing trend of drugs and substances abuse (DSA) by different age groups and gender in parts of Kenya is not only a socio-economic problem but a public health concern. There is a need to determine prevalence, types and patterns of DSA by age and gender in order to develop all-inclusive and long-term strategies to prevent and manage the DSA within different communities. In this study we determined the prevalence of DSA, types and patterns of drugs and substances being abused and risk factors associated with this abuse. A descriptive cross-sectional mixed methods study was conducted in four counties; Isiolo, Kajiado, Murang'a and Nyamira, all purposively selected from the 47 counties of Kenya based on the review reports of the Kenya Medical Research Institute's County Cluster Coordinators which indicated that DSA was a priority health concern in the selected counties. From each county, two sub-locations each from two locations in one sub-county were purposively selected. In each sub-location, 225 households were systematically selected. Hence, a total of 3,600 participants were systematically sampled for quantitative data collection using an interviewer-based questionnaire to gather information on magnitude and causes of DSA. Additionally, in each county, qualitative data through in-depth interviews (IDIs) with 16 opinion leaders, 16 healthcare personnel, 16 previous DSAs, at least 5 county personnel, 32 current DSAs; and through 16 focus group discussions (FGDs) were concurrently collected to elicit more information on types, patterns and causes of DSA. The observed overall prevalence of DSA was calculated using binomial logistic regression model and factors associated with DSA analyzed using multilevel logistic regression model. Qualitative data was analyzed using QSR NVIVO version 10, thematically by types, patterns and causes of DSA by age and gender. Prevalence of DSA was 86.0% (95%CI: 84.9-87.2) with the highest prevalence being observed in Nyamira County, 89.8% (95%CI: 87.9-91.7). Age-wise, the highest prevalence was observed in persons aged between 45 to 53 years, 89.4% (95%CI: 86.9-92.0), followed by those aged 36 to 44 years, 88.0% (95%CI: 85.4-90.6). Majority of those who abuse drugs and substances were males; 94.5% (95%CI: 93.6-95.4). The most abused drugs or substances were packaged/legal alcohol at 25.2% (745), cigarettes 20.3% (600), local brew (chang'aa) 16.3% (482), and khat (miraa) 10.5% (311). Risk factors analysis revealed that DSA was significantly higher among males (adjusted odds ratio (aOR) = 7.02 (95%CI: 5.21-9.45), p<0.001), government employees (aOR = 2.27 (95%CI: 1.05-4.91), p = 0.036) and unmarried (aOR = 1.71 (95%CI: 1.06-2.77), p = 0.028). These study findings are useful in informing development of specific control programmes which will address age, gender and county needs of DSA in Kenya in order to comprehensively respond to this public health problem. This study was conducted in line with the Kenya National Authority for the Campaign against Alcohol and Drug Abuse (NACADA) mandate to promote use of research on drugs and substances abuse.