Mixed-order Model Research Articles

Locally enhanced mixed-order model for chloramine decay in drinking water disinfection

Chloramine is the second most popular disinfectant and is widely used in the disinfection of drinking water. For chloramine disinfection, some standards require the total chlorine concentration to be maintained in an appropriate range in the water distribution system. Therefore, exploring the mechanism of chloramine decay and deriving an accurate chloramine decay model helps to optimize the disinfection process and ensure water quality safety. This paper proposed a locally enhanced mixed-order(LEM) model consisting of the first order model and the mixed order model to describe chloramine auto-decomposition and decays caused by other reactions respectively. Via proving the parameter a and k2 related to temperatures instead of initial chloramine concentration, the model had been further simplified. Nine chloramine decay experiments with different initial chloramine concentrations and temperatures were designed and carried out to evaluate the new model performance for chloramine decay simulation. The research results showed that the simplified LEM model could simulate the whole process of chloramine decay well. Its accuracy evaluation indexes (R2 and SSE) were better than that obtained from the first order model and the mixed order model. This paper proposed a simple and accurate method to simulate the process of chloramine decay and had a guiding significance for water quality safety assurance.

Biochar-layered double hydroxide composites for the adsorption of tetracycline from water: synthesis, process modeling, and mechanism.

Antibiotic-contaminated water is a crucial issue worldwide. Thus, in this study, the MgFeCa-layered double hydroxides were supported in date palm-derived biochar (B) using co-precipitation, hydrothermal, and co-pyrolysis methods. It closes gaps in composite design for pharmaceutical pollutant removal, advances eco-friendly adsorbents, and advances targeted water cleanup by investigating synthesis methodologies and gaining new insights into adsorption. The prepared B-MgFeCa composites were investigated for tetracycline (TC) adsorption from an aqueous solution. The B-MgFeCa composites synthesized through co-precipitation and hydrothermal methods exhibited better crystallinity, functional groups, and well-developed LDH structure within the biochar matrix. However, the co-pyrolysis method resulted in the LDH structure breakage, leading to the low crystalline composite material. The maximum adsorption of TC onto all B-MgFeCa was obtained at an acidic pH range (4-5). The B-MgFeCa composites produced via hydrothermal and co-pyrolysis methods showed higher and faster TC adsorption than the co-precipitation method. The kinetic results can be better described by Langmuir kinetic and mixed order models at low and high TC concentrations, indicating that the rate-limiting step is mainly associated with active binding sites adsorption. The Sip and Freundlich models showed better fitting with the equilibrium data. The TC removal by B-MgFeCa composites prepared via hydrothermal, the highest estimated uptake which is around 639.76 mg.g-1 according to the Sips model at ambient conditions, and co-pyrolysis was mainly dominated by physical and chemical interactions. The composite obtained via the co-precipitation method adsorbed TC through chemical bonding between surface functional groups with anionic species of TC molecule. The B-MgFeCa composite showed excellent reusability performance for up to five cycles with only a 30% decrease in TC removal efficiency. The results demonstrated that B-MgFeCa composites could be used as promising adsorbent materials for effective wastewater treatment.

The mixed-order chlorine decay model with an analytical solution and corresponding trihalomethane generation model in drinking water

Ensuring effective drinking water disinfection, remaining a certain amount of residual chlorine, and controlling disinfection by-product formation were very important for guarantying water quality safety and protecting public health; thus, the chlorine decay model and corresponding disinfection by-product formation model were necessary. This paper proposed a mixed-order chlorine bulk decay model (two parameters) based on Taylor's formula and derived its analytical solution. The accuracy of the mixed-order model was evaluated by comparing it with the nth-order model. To optimize the model and reduce the number of parameters required to be calibrated, the relationship of parameters with temperature, initial chlorine concentration, TOC and inorganic substance (ammonia nitrogen and iodide ion) was explored. The result proved that one of the parameters could be regarded as temperature dependent only. Meanwhile, the temperature equation of the model parameters was established by the Arrhenius formula. Subsequently, this paper selected trihalomethane as the target and study the linear relationship between chlorine consumption and trihalomethane formation. The results indicated that the liner slope had little correlation with initial chlorine concentration and temperature. On this basis, the corresponding trihalomethane model was built and its performance was proven to be good. The modeling developed in this work could be applied to drinking water distribution systems for residual chlorine and trihalomethane prediction, and provided a reference for the decision involving water quality.

Nitrogen-rich based conjugated microporous polymers for highly efficient adsorption and removal of COVID-19 antiviral drug chloroquine phosphate from environmental waters

Chloroquine phosphate (CQP) has been suggested as an important and effective clinical reliever medication for the 2019 coronavirus (COVID-19). Nevertheless, its excessive use will inevitably cause irreparable damage to the entire ecosystem, thereby posing a considerable environmental safety concern. Hence, the development of highly-efficient methods of removing CQP from water pollution sources, e.g., effluents from hospitals and pharmaceutical factories is significant. This study reported the fabrication of novel CN bond linked conjugated microporous polymers (CMPs) (BPT–DMB–CMP) with multiple nitrogen-rich anchoring sites for the quick and efficient removal of CQP from aqueous solutions. The irreversible covalent CN bond linked in the internal framework of BPT–DMB–CMP endowed it with good chemical stability and excellent adsorbent regeneration. With its predesigned functional groups (i.e., rich NH bonds, triazine rings, and benzene rings) and large area surface (1,019.89 m2·g−1), BPT–DMB–CMP demonstrated rapid adsorption kinetics (25 min) and an extraordinary adsorption capacity (334.70 mg·g−1) for CQP, which is relatively higher than that of other adsorbents. The adsorption behavior of CQP on BPT–DMB–CMP corresponded with Liu model and mixed-order model. Based on the density functional theory (DFT) calculations, X-ray photoelectron spectroscopy (XPS), and adsorption comparisons test, the halogen bonding, and hydrogen bonding cooperates with π − π, C H···π interactions and size-matching effect in the CQP adsorption system on BPT–DMB–CMP. The excellent practicability for the removal of CQP from real wastewater samples verified the prospect of practical application of BPT–DMB–CMP. BPT–DMB–CMP exhibited the application potentials for the adsorption of other antiviral drugs. This work opens up an efficient, simple, and high adsorption capacity way for removal CQP.

Actigraphy-Derived Sleep Profiles of Children with and without Attention-Deficit/Hyperactivity Disorder (ADHD) over Two Weeks-Comparison, Precursor Symptoms, and the Chronotype.

Although sleep problems are common in children with ADHD, their extent, preceding risk factors, and the association between neurocognitive performance and neurobiological processes in sleep and ADHD, are still largely unknown. We examined sleep variables in school-aged children with ADHD, addressing their intra-individual variability (IIV) and considering potential precursor symptoms as well as the chronotype. Additionally, in a subgroup of our sample, we investigated associations with neurobehavioral functioning (n = 44). A total of 57 children (6–12 years) with (n = 24) and without ADHD (n = 33) were recruited in one center of the large ESCAlife study to wear actigraphs for two weeks. Actigraphy-derived dependent variables, including IIV, were analyzed using linear mixed models in order to find differences between the groups. A stepwise regression model was used to investigate neuropsychological function. Overall, children with ADHD showed longer sleep onset latency (SOL), higher IIV in SOL, more movements during sleep, lower sleep efficiency, and a slightly larger sleep deficit on school days compared with free days. No group differences were observed for chronotype or sleep onset time. Sleep problems in infancy predicted later SOL and the total number of movements during sleep in children with and without ADHD. No additional effect of sleep problems, beyond ADHD symptom severity, on neuropsychological functioning was found. This study highlights the importance of screening children with ADHD for current and early childhood sleep disturbances in order to prevent long-term sleep problems and offer individualized treatments. Future studies with larger sample sizes should examine possible biological markers to improve our understanding of the underlying mechanisms.

Oxidative coupling of Kraft lignin mediated with hypervalent iodine reagent (III) for enhanced removal of dye in water

One of the most attractive routes to valorize lignin is to prepare lignin-based materials which can be used as high-value products, such as dye absorbents. Various processes have been investigated to improve the properties of lignin. In this study, a hypervalent iodine reagent (III) was employed to achieve oxidative coupling of Kraft lignin (KL). The structural changes were investigated by FTIR, quantitative 31P NMR, 2D-HSQC, and GPC. Oxidative coupling between lignin aromatic C(sp2)H bonds and aromatic C(sp2)-H functionalization with aliphatic hydroxyl group occurred via inter- or intramolecular modes, with resultant decreases of the aromatic protons and hydroxyl groups. In addition, selective modification of aliphatic OH groups in β-O-4′ linkages occurred leading to the formation of aromatic carbonyl groups. Increases in molecular weights with the appearance of conjugated CO groups were also observed. The oxidative crosslinked lignin (KL-2.0) exhibited better adsorptive features for brilliant green (251.2 mg/g) than that of unmodified KL (59.4 mg/g). Their adsorption kinetics were investigated by pseudo-first-order, pseudo-second-order and mixed-order models. Furthermore, the Langmuir and Freundlich models were employed to study the adsorption isotherms.

Conductive mixed-order generalized dispersion model for noble metals in the optical regime.

Various dispersion models can be expressed as special cases of the Generalized Dispersion Model (GDM), which is composed of a series of Padé polynomials. While important for its broad applicability, we found that some materials with Drude dispersive terms can be accurately modeled by mixing a 1st order Padé polynomial with an extra conductivity term. This conductivity term can be separated from the auxiliary differential equation (ADE). Therefore, the proposed mixed-order model can achieve the same accuracy with fewer unknowns, thus realizing higher computational efficiency and lower memory consumption. For examples, we derive the model parameters and corresponding numerical errors for noble metals including Au, Ag, and Al in the optical regime. Finally, the proposed model's efficiency improvements are validated through implementation within a Discontinuous Galerkin Time Domain (DGTD) framework. The proposed model can achieve up to 12.5% efficiency improvement in theory compared to the conventional GDM with the same accuracy. A numerical example validates that, in practice, 9% memory reduction and 11% acceleration can be realized.

A new thermoluminescence mixed order model considering thermal ‎quenching effect

Thermal quenching as an important and well-known effect in compounds exhibiting thermoluminescence, should be considered in thermoluminescence studies. Among the models describing the thermoluminescence phenomenon, the mixed order kinetic model provides a more realistic description of this behavior. In this work, the Thermal quenching effect is included in the mixed order kinetic model and the new thermoluminescence glow curve deconvolution function is obtained in terms of the maximum intensity and the maximum intensity temperature. The new equation reduces to the known mixed order model by equating the thermal quenching parameter to zero. Also the kinetic parameters of the peak 5 of LiF: Mg, Ti (TLD-100) thermoluminescence dosimeter considering the new equation (with Thermal quenching effect) and the previous equation (without Thermal quenching effect) for different heating rates are determined and the results are compared.

Cost-effectiveness and implementation process of a running-related injury prevention program (RunIn3): Protocol of a randomized controlled trial

BackgroundRunning is one of the most popular and accessible physical activities in the world. However, running-related injuries are unfortunately very common. Scientific evidence is limited and scarce regarding (cost-)effectiveness and implementation process of interventions for running-related injuries prevention. Thus, the objective of this study will be to investigate the effectiveness, cost-effectiveness and implementation process of a running-related injury prevention program (RunIn3). MethodsThis is the protocol of a pragmatic hybrid type 1 randomized controlled trial. There will be 530 runners over 18 years old, without running-related injuries in the last 3 months from São Paulo, Brazil. This program will be delivered online with two broad actions: (1) to provide feedback on individual training characteristics and running-related injury risk; and (2) providing/enhancing knowledge, skills and self-efficacy on running-related injury preventive behaviors. The primary outcome will be the proportion of runners reporting running-related injuries. The secondary outcomes will be preventive behaviors, direct and indirect costs, and implementation outcomes. The main effectiveness analysis on the primary outcome will be performed using linear probability mixed models in order to allow outcome changes over time and to yield the absolute risk reduction between-groups. DiscussionThe main hypothesis of this study is that the RunIn3 program will be effective in reducing the running-related injury risk and in promoting preventive behavior, either by increasing the frequency of healthy behaviors or by reducing the frequency of risk behaviors. Moreover, if the RunIn3 program is effective in reducing the running-related injuries risk, we believe that this effect would go alongside with a reduction of societal costs. Trail registrationClinicaltrials.gov (NCT03892239) Registered 5 February 2019 - Prospectively registered, https://clinicaltrials.gov/ct2/show/NCT03892239.

Photocatalysis of naphthalene by Fe3O4/Oxone/UV: Simultaneous radical and non-radical pathways

Naphthalene (Nap) degradation by photocatalysis of Fe3O4/Oxone/UV was studied. The system eliminated Nap in 30 min and the kinetics is described by a novel mixed order model with adsorption and decay dominant rate constants, representing non-radical and radical pathways respectively. The reaction is dominated by catalysis in acidic pHs as Oxone anions are adsorbed onto the protonated Fe3O4 surface for activation; In alkaline solution, the adsorption of Nap to the deprotonated Fe3O4 surface is the main removal pathway. The catalyst was reused for 5 cycles and the performance was enhanced after reuse. XPS study confirmed that the surface Fe content of Fe3O4 remained stable after reusing due to the effective UV-assisted ≡FeII—≡FeIII catalytic cycle. An additional C‒O bond on Fe3O4 surface was detected after reuse, which is proposed to be an OH bond on catalyst as an extra adsorption site and for radical generation.

A coupled RTD and mixed-order kinetic model to predict high rate algal pond wastewater treatment under different operational conditions: Performance assessment and sizing application

A coupled residence time distribution (RTD) and mixed-order model was developed to simulate the performance of a pilot high rate algal pond (HRAP) for wastewater treatment under different operational conditions requiring simple influent and effluent wastewater characteristics as input data. The model showed potential in general assessment of the HRAP system performance, successfully capturing the magnitude as well as general trend of COD, TKN, TN and TP concentrations with acceptable accuracy (Nash-Sutcliffe Efficiency (NSE) value up to 0.99). However, due to the common limitation of black box model type, the detailed agreement between model and experimental data was highly varied, sometime unsatisfactory performance (NSE < 0) was obtained, especially for highly complex processes like TKN or TN removal. Besides, general information on the dynamics of algal bacterial processes under different operational conditions could be revealed by analyzing calibrated reaction order n and reaction rate constant kn values with higher n value corresponding to higher complexity of the process and higher kn values associating with higher removal rate. Moreover, the model could also be used as a quick and convenient support for HRAP design and construction by providing estimated hydraulic retention time (HRT) values required for single HRAP system treating wastewater in different case studies. Further validation with outdoor HRAP system is necessary to increase the accuracy of the model prediction.

Magnetic COFs for the adsorptive removal of diclofenac and sulfamethazine from aqueous solution: Adsorption kinetics, isotherms study and DFT calculation

Covalent organic frameworks (COFs) are emerging and promising adsorbents for the adsorptive removal of many types of pollutants. However, most COFs fabricated by various methods are in the form of microcrystalline powders, making them difficult in separation. In this study, magnetic COFs were prepared by a simple impregnation method. The as-prepared samples with Ms = 5.2 emu g−1 showed a good magnetic separation capability. Additionally, the adsorption performance of magnetic COFs towards antibiotics (e.g., diclofenac and sulfamethazine) was also studied. Various adsorption kinetic models (e.g., the pseudo first-order, the pseudo second-order, and mixed-order models) and adsorption isotherm models (e.g., the Freundlich, the Langmuir, and the Sips models) were used to study their adsorption kinetics and isotherms. Furthermore, density functional theory (DFT) was utilized to predict the interaction between adsorbents and adsorbates and to explain the partial adsorption mechanisms.

Ferrous ion mitigates the negative effects of humic acid on removal of 4-nitrophenol by zerovalent iron

In this study, Fe2+ addition was employed to overcome the negative effects of humic acid (HA) on contaminant removal by zerovalent iron (ZVI), and its feasibility to improve electron efficiency of ZVI was also tested. HA at high concentrations suppressed the removal of 4-nitrophenol (4-NP) by ZVI, while the addition of 0.25–1.0 mM Fe2+ could greatly mitigate this inhibitory effect and enhance 4-NP reduction. Specifically, with a mixed-order model, global fitting results showed that the addition of Fe2+ increased the rate constant from 0.124 × 10−2–0.219 × 10−2 mM/min to 0.227 × 10−2–0.417 × 10−2 mM/min and shortened lag period from 19.7–47.9 min to 8.0–15.2 min for 4-NP removal. The mechanistic investigation revealed this trend could be explained by the following aspects: i) Fe2+ can facilitate the generation of Fe(II)-containing oxides, which can act as an electron mediator or direct electron donor for 4-NP reduction; ii) the presence of Fe2+ could lead to aggregation of HA particles and accordingly reduced its coverage on ZVI surface. But the results of respike experiments indicate that Fe2+ addition did not show remarkable effect on the electron efficiency of 4-NP by ZVI, which should be associated with that Fe2+ was not able to favor the enrichment of 4-NP on ZVI surface.

Application of a Mixed Order Model to Determine the Rate Adsorption of 1-Nitronaphthalene onto Activated Carbon

This study investigated the adsorption kinetics of 1-nitronaphthalene solution (a polycyclic aromatic hydrocarbon, PAH) onto seven different masses of activated carbon. The coefficient of determination (r2) was used to determine the best-fit kinetic model and to confirm agreement between experimental data and the kinetic rate equations. The results indicated that adsorption could be defined with masses of 0.0200 g and 0.0501 g when fitted using a second order rate equation. Adsorption on to masses of 0.1003 g, 0.1203, 0.1501 g, and 0.2001 g was best defined when data were fitted to a pseudo second order rate equation. However, adsorption onto a mass of 0.0701g did not fit with any simple rate law. Consequently, a new mathematical mixed order equation was developed to determine the rates of adsorption and the rate constants by combining two orders of equations: the pseudo first order and pseudo second order, to achieve a better fit with the same data.

Global congruence between cuckoo species richness and biodiversity hotspots

Considering loss of biodiversity a global threat, cost-effective tools for monitoring spatial distribution of species are relevant for conservation planning. The aims of this study were (a) to compare the global pattern of species richness in Cuculidae with species richness of birds, amphibians and mammals; (b) whether it is spatially congruent with hotspot areas of biodiversity at a global scale; and (c) whether the distribution of night light intensity reflecting human population density is associated with cuckoo species richness. We mapped the global distribution of all cuckoo species, classified as parasitic or non-parasitic species. Species richness was calculated at a fixed spatial scale for: Cuculidae, amphibians, birds and mammals. We applied Generalized Linear Mixed Models in order to explore the associations between species richness of each group of animals, night light intensity and hotspots of biodiversity areas at a global scale.Worldwide patterns of species richness of parasitic and non-parasitic cuckoos reflected species richness of birds, amphibians and mammals. In addition, and importantly, species richness of cuckoos was spatially congruent with hotspot areas of biodiversity across the world. Finally, night light intensity was slightly positively associated with species richness of parasitic cuckoos. Our findings confirmed that cuckoos constitute an important surrogate of high species richness of different animal taxa at a global scale: It is easy to learn how to identify cuckoos, whereas other species of birds, mammals or amphibians can only be identified by specialists. Our findings also suggest that other parasitic cuckoo species can be used as a biodiversity surrogate in a similar way as the common cuckoo in Eurasia.

Identification of Sex-Specific Transcriptome Responses to Polychlorinated Biphenyls (PCBs)

PCBs are classified as xenoestrogens and carcinogens and their health risks may be sex-specific. To identify potential sex-specific responses to PCB-exposure we established gene expression profiles in a population study subdivided into females and males. Gene expression profiles were determined in a study population consisting of 512 subjects from the EnviroGenomarkers project, 217 subjects who developed lymphoma and 295 controls were selected in later life. We ran linear mixed models in order to find associations between gene expression and exposure to PCBs, while correcting for confounders, in particular distribution of white blood cells (WBC), as well as random effects. The analysis was subdivided according to sex and development of lymphoma in later life. The changes in gene expression as a result of exposure to the six studied PCB congeners were sex- and WBC type specific. The relatively large number of genes that are significantly associated with PCB-exposure in the female subpopulation already indicates different biological response mechanisms to PCBs between the two sexes. The interaction analysis between different PCBs and WBCs provides only a small overlap between sexes. In males, cancer-related pathways and in females immune system-related pathways are identified in association with PCBs and WBCs. Future lymphoma cases and controls for both sexes show different responses to the interaction of PCBs with WBCs, suggesting a role of the immune system in PCB-related cancer development.

Recruit Fitness as a Predictor of Police Academy Graduation.

BackgroundSuboptimal recruit fitness may be a risk factor for poor performance, injury, illness, and lost time during police academy training.AimsTo assess the probability of successful completion and graduation from a police academy as a function of recruits’ baseline fitness levels at the time of academy entry.MethodsRetrospective study where all available records from recruit training courses held (2006–2012) at all Massachusetts municipal police academies were reviewed and analysed. Entry fitness levels were quantified from the following measures, as recorded at the start of each training class: body composition, push-ups, sit-ups, sit-and-reach, and 1.5-mile run-time. The primary outcome of interest was the odds of not successfully graduating from an academy. We used generalized linear mixed models in order to fit logistic regression models with random intercepts for assessing the probability of not graduating, based on entry-level fitness. The primary analyses were restricted to recruits with complete entry-level fitness data.ResultsThe fitness measures most strongly associated with academy failure were lesser number of push-ups completed (odds ratio [OR] = 5.2, 95% confidence interval [CI] 2.3–11.7, for 20 versus 41–60 push-ups) and slower run times (OR = 3.8, 95% CI 1.8–7.8, [1.5 mile run time of ≥15′20″] versus [12′33″ to 10′37″]).ConclusionsBaseline pushups and 1.5-mile run-time showed the best ability to predict successful academy graduation, especially when considered together. Future research should include prospective validation of entry-level fitness as a predictor of subsequent police academy success.

Using ground observations of a digital camera in the VIS-NIR range for quantifying the phenology of Mediterranean woody species

The spectral reflectance of most plant species is quite similar, and thus the feasibility of identifying most plant species based on single date multispectral data is very low. Seasonal phenological patterns of plant species may enable to face the challenge of using remote sensing for mapping plant species at the individual level. We used a consumer-grade digital camera with near infra-red capabilities in order to extract and quantify vegetation phenological information in four East Mediterranean sites. After illumination corrections and other noise reduction steps, the phenological patterns of 1839 individuals representing 12 common species were analyzed, including evergreen trees, winter deciduous trees, semi-deciduous summer shrubs and annual herbaceous patches. Five vegetation indices were used to describe the phenology: relative green and red (green\\red chromatic coordinate), excess green (ExG), normalized difference vegetation index (NDVI) and green-red vegetation index (GRVI). We found significant differences between the phenology of the various species, and defined the main phenological groups using agglomerative hierarchical clustering. Differences between species and sites regarding the start of season (SOS), maximum of season (MOS) and end of season (EOS) were displayed in detail, using ExG values, as this index was found to have the lowest percentage of outliers. An additional visible band spectral index (relative red) was found as useful for characterizing seasonal phenology, and had the lowest correlation with the other four vegetation indices, which are more sensitive to greenness. We used a linear mixed model in order to evaluate the influences of various factors on the phenology, and found that unlike the significant effect of species and individuals on SOS, MOS and EOS, the sites' location did not have a direct significant effect on the timing of phenological events. In conclusion, the relative advantage of the proposed methodology is the exploitation of representative temporal information that is collected with accessible and simple devices, for the subsequent determination of optimal temporal acquisition of images by overhead sensors, for vegetation mapping over larger areas.

Association between electrical conductivity and milk production traits in Dairy Gyr cows

ABSTRACTThis study investigated the association of electrical conductivity (EC) of milk with milk production and composition traits in Dairy Gyr cows. Monthly milk samples were collected on the official milk recording day for laboratory analysis of somatic cell count, EC and milk composition. A total of 680 samples from 268 cows belonging to eight herds in the southeastern region of Brazil were collected between January and July 2012. Traits were analysed by the restricted maximum likelihood method using mixed models in order to associate EC and somatic cell score (SCS) with the other traits. Mean EC and SCS were 4.90 mS/cm and 4.66, respectively, and the correlation between these traits was 0.41. Linear regression of EC on SCS indicated an increase in EC of 0.094 mS/cm per SCS. Despite the relationship between EC and SCS, the former analysed only on the official recording day may not be a reliable method for the diagnosis of mastitis. However, EC could be used as an auxiliary trait in the analysis of mastitis resistance simultaneously with somatic cell count since, in addition to the association between these two traits, the measurement of EC is an inexpensive, simple and rapid method.

Sequence Prediction With Sparse Distributed Hyperdimensional Coding Applied to the Analysis of Mobile Phone Use Patterns

Modeling and prediction of temporal sequences is central to many signal processing and machine learning applications. Prediction based on sequence history is typically performed using parametric models, such as fixed-order Markov chains ( n -grams), approximations of high-order Markov processes, such as mixed-order Markov models or mixtures of lagged bigram models, or with other machine learning techniques. This paper presents a method for sequence prediction based on sparse hyperdimensional coding of the sequence structure and describes how higher order temporal structures can be utilized in sparse coding in a balanced manner. The method is purely incremental, allowing real-time online learning and prediction with limited computational resources. Experiments with prediction of mobile phone use patterns, including the prediction of the next launched application, the next GPS location of the user, and the next artist played with the phone media player, reveal that the proposed method is able to capture the relevant variable-order structure from the sequences. In comparison with the n -grams and the mixed-order Markov models, the sparse hyperdimensional predictor clearly outperforms its peers in terms of unweighted average recall and achieves an equal level of weighted average recall as the mixed-order Markov chain but without the batch training of the mixed-order model.